The needs analysis stage was conducted with a semi-structured interview with one vocational counseling guidance teacher, "X," Surakarta. Based on interviews, it was found that in the last five years, there have been cases of female students who have had an out-of-wedlock pregnancy, which caused them to be forced to resign from school. Although the school has made efforts to control the sexual behavior of students, teachers still find physical interactions between male and female students involving touching sensitive body parts. The findings of this preliminary study indicate the phenomenon of early marriage and active premarital sexual behavior among students of SMK "X" in the city of Surakarta, so intervention through sexual education is needed as a measure to prevent early marriage.

Then, the researcher screened the level of early marriage intention by spreading the scale of early marriage intention. Screening of the level of early marriage intention was carried out on 261 students of SMK "X" Surakarta (15-18 years old). The results showed that 92 out of 261 students (35.34%) had participated in a sexual education program before. However, it is known that there are still 104 students (39.84%) who have moderate early marriage intentions, 58 students (22.22%) have high early marriage intentions, and 15 students (5.74%) have very high early marriage intentions. It is because the sexual education provided is still focused on biological aspects and sexually transmitted diseases only. Therefore, SMK "X" Surakarta students still need more comprehensive educational materials.

The material in the Serat Widya Pramana Sexual Education E-comic results from exploring the content of Widya Pramana's Serat, previously carried out in a preliminary study by (Dewantari et al., 2024). The material is divided into 6 chapters, namely physical development (Pupuh Kinanthi), sexual development (Pupuh Dhandhanggula), psychological development (Pupuh Sinom and Dhandhanggula), sexually transmitted diseases (Pupuh Kinanthi), choice of partners (Pupuh Kinanthi and Sinom), and marriage (Pupuh Sinom and Dhandhanggula). The exploration results have been validated by literary material experts, namely lecturers of the Regional Literature study program, Faculty of Cultural Sciences, Sebelas Maret University, with a score of 80 (good).

Furthermore, in a preliminary study by (Dewantari et al., 2023), Healthy reproductive material has been prepared in the form of modules that have been tested for validity by lecturers of the Midwifery study program, Faculty of Medicine, Sebelas Maret University, with a percentage value of 68 (good). Therefore, the researcher reuses the material in the module.

The E-comic Sera & Sora: Exploring the World of Teens was developed into seven episodes based on the exploration and relevance testing results. These episodes include character introductions and discussions about various aspects of adolescent development, namely physical, sexual, psychological development, sexually transmitted diseases, partner selection, and marriage (Dewantari et al., 2024).

The material presented in the physical development episode includes the early age of physical changes in adolescents according to Serat Widya Pramana, physical development characteristics in adolescent boys and girls, and various problems that may arise due to these changes. The episode of sexual development reviews the age at which sexual aspects begin to develop in adolescents and the hormonal changes that occur in both men and women based on the same teachings.

Meanwhile, the episode of psychological development discusses the teachings of Serat Widya Pramana regarding the formation of adolescent character and its philosophical values, the important role of parents in accompanying psychological development, and the prohibition of marriage in adolescence and its impact on mental health. The episode of sexually transmitted diseases highlights diseases that can arise due to premarital sex behavior, according to the philosophical view in Serat Widya Pramana.

Furthermore, in the episode of choosing a partner, a guide from Serat Widya Pramana is explained about the criteria for an ideal partner and its philosophical basis, the risk of diseases that can be inherited, the prohibition of marriage with relatives and the risks, and the ideal age in choosing a partner and the potential risks. Finally, the wedding episode explores the importance of emotional and mental maturity in preparing for marriage, the ideal age for marriage, the need to weigh the motivation for marriage, and the readiness that must be had before entering married life.

The design stage is continued by compiling a verbal idea containing the central theme sourced from the substance of the material from the exploration of the content of Serat Widya Pramana, which has been carried out by Dewantari et al (2024), which is developed into a simple story structure in each episode as seen on Table 5.

The next stage is to design a visual idea by determining the lettering style as bubble text for character dialogue. Bubble text is not only a circle with a dialogue tail, but also has a variety of shapes to represent the character's feelings, such as worry, upset, confused, and so on (Figure 1.A). In addition to bubble text, lettering is used as a symbol of captions by using text boxes to describe relevant characters, context, and story background (Figure 1.B). Splash giving. Useful for sound effect replacements. This effect supports the story's atmosphere so that comic readers can feel the atmosphere in the comic (Figure 1.C).

In this comic's design, the characters aim to represent two teenage twins with a color palette adjusted to the characteristics of identical colors. This depiction of characters according to identical colors was chosen to reflect the character's gender. Blue is for male twin characters, and pink is for female twin characters.

The development stage consists of e-commerce design development, expert validation, feasibility testing of potential users, and data analysis.

First, development of layout sketches, illustration panels, and text bubbles.The panels are based on design principles by paying attention to composition, emphasis, readability, and clarity. The reading direction on the panel adjusts to the format of the designed comic, i.e., vertical web comics. The panels are assembled in order according to the structure of the story or script that has been created. The researcher draws comics based on the script that has been made, and rough sketches function to minimize errors in making comics.

Second, outline creation. The rough sketches made in the previous stage will be tidied up so they can proceed to the coloring stage. Outlines provide clear boundaries on objects, making them appear more assertive and easy to read. The provision of dialogue sketches is made so that the process of finishing/rendering (after coloring) is more straightforward in the process of typsetting (setting/typography) of the dialogue.

Third, coloring. Coloring starts by coloring all the outlines in a very dark brown color to reduce the roughness of using only black outlines. Then, all characters or objects on the panel will be given green blocks to mark, making the coloring process easier digitally. Color blocks are functional for clipping techniques on each layer, so nothing comes out of the blocked area when given the next color. Researchers give basic colors such as skin color, hair color, shirt color, etc. Shadow and light colors are then given to give dimension to the image. The color used is saturated.

Fourth, background provision.The background is adapted to the atmosphere and context of the story. The background is not only in the form of a place, but it can also be done by playing with colors to make the comic look attractive and not too crowded.

Fifth, texting and polishing. This process has entered the text-giving stage by giving and tidying up the location of conversation text bubbles, character words, narrative boxes, and character mind text balloons. After that, the researcher performed the final polish after administering the text.

Sixth, rendering. Rendering involves downloading the final episode according to a format adjusted to the appearance of the Google site. The format used is RGB color because comics do not need to be printed as physical books, but in e-comics, 600 px resolution, and A5 size paper.

Seventh, uploading. At this stage, the comic is uploaded through a website created by the research team. Because it is still in development, this e-comic website will only be accessible to research subjects and research teams.

Furthermore, an assessment of the feasibility of e-comic products is carried out in terms of grammar, media, and potential users. The feasibility assessment in grammar is carried out by linguists who have obtained a master's degree in education, with the results seen in Table 6.

In Table 4, it is stated that the assessment by linguists got a score of 24, which was then converted into a scale of 1-100, so that a score of 96 was obtained in the excellent category. Suggestions and improvements are given (Table 5) so that, in terms of language, this is worthy of inclusion, but with minor revisions.

After going through the validation stage by linguists, the validation stage by media experts continues. The media expert in this assessment is a lecturer in the Visual Communication Design study program, Faculty of Fine Arts and Design, Sebelas Maret University, with the results presented in Table 8.

In Table 6, it is stated that the assessment by media experts obtained a score of 90, with the category of very good. Suggestions are given (Table 7) for further research.

After media experts carry out the validation stage, potential users carry it out. The validation stage by potential users contains indicators of writing display, image display, comic function, and comic benefits. Ten students become potential user validators with the results that are shown in Table 10.

In Table 8, it is stated that the assessment by ten prospective users obtained a score of 69.3 with a good category (not revised/valid). Suggestions were given to change the form of the media and extend the episode, but it was not done. After the validation stage, the development of the e-comic can be continued to the pilot testing stage. The development of sexual education e-comic Serat Widya Pramana at the pilot testing stage was applied to 10 subjects, namely 4 women and 6 men. This study consisted of two data pairs: sexual knowledge and early marriage intention.

Before the paired sample t-test, a basic assumption test, including a data normality test, is carried out first. Normality testing of research data was carried out using Shapiro-Wilk analysis because the sample amounted to < 50. If the results show a p>0.05 value, then the research data is distributed normally. The results of the data normality test can be seen in Table 11.

Based on the results of the test using Shapiro-Wilk, it is known that the pre-test of sexual knowledge has a value of p = 0.438 >0.05 and the post-test of sexual knowledge has a value of p = 0.310>0.05, so it can be concluded that the data of this study meets the assumption of normality. To determine the significance of the influence of the implementation of the sexual education program through e-comics on students, a paired sample t-test was conducted, with the results of which can be seen in Table 12.

Based on the paired sample t-test analysis, the score showed that there was a significant difference between sexual knowledge before reading e-comics (M = 12.9; SD = 2.42) and sexual knowledge after reading e-comics (M = 22.6; SD = 1.90) with p = 0.000 (p<0.05). Sexual knowledge scores have increased significantly, so that learning with e-comics can increase sexual knowledge in adolescents. In addition, the results of the paired sample t-test analysis also showed that there was a significant difference between the intention to marry early before reading the e-comic (M = 58.2; SD = 7.46) and intention to marry early after reading e-comics (M = 47.9; SD = 13.31) with p=0.008 (p<0.05). The score of early marriage intention has decreased significantly, so learning with e-comics can reduce early marriage intentions in adolescents.

The development of this sexual education e-comic has been carried out through several stages. First, needs analysis and material analysis are carried out for the e-comic that will be developed. Analyzing needs is important in designing a product so that the results can be used as the basis for the development process according to the needs in the field (Afifulloh & Cahyanto, 2021). By screening, the level of early marriage intention of SMK "X" students in Surakarta is known. However, 35.24% of students have participated in sexual education programs before; there are still 67.8% of students with moderate-very high levels of intention.

This result shows the need for more comprehensive sexual education materials. Comprehensive sexuality education is not limited to providing information alone, but adolescents need to be allowed to acquire life skills and develop positive attitudes and values (Nadya, 2024). Therefore, culturally-based sexual education is appropriate and needed by adolescents. Culture-based sexual education contains knowledge and skills that should pay attention to the culture that already exists and is formed in society (Nadya, 2024).

After going through the analysis stage, the next stage is design. The design stage in e-commerce development includes planning verbal and visual ideas. The third stage in developing this e-comic is the development of verbal and visual ideas that have been prepared. Then, the e-comic was validated by linguists who were lecturers in the field of Indonesian, a media expert who was a lecturer in the field of Visual Communication Design, and 10 prospective users to assess their feasibility. The results of the linguistic validation obtained a score of 96, or very good. The linguist's assessment gets perfect scores on the aspect of the language used, suitable for teenagers, sentences are easy to understand, sentences do not contain double meanings, and the accuracy of the use of terms is an advantage of this e-comic. Assessments by media experts also received a score of 90 or very good. In addition, the assessment of potential users obtained an average score of 69.3, or good, and did not need revision.

The researcher then conducted a limited-scale trial, or Pilot Testing. Trials are carried out to test the feasibility, effectiveness, and practicality of the product that has been developed (Suttrisno & Puspitasari, 2021). Phase Pilot Testing can bridge the initial development step to wider implementation by evaluating and identifying obstacles and limitations. Based on the results of the data analysis and pilot Testing, it was found that there was a significant difference between the level of sexual knowledge and early marriage intentions before and after reading the e-comic. Adolescents' sexual knowledge levels increase after reading an e-comic with a significance value p=0.000 (p<0.05), while the level of intention for early marriage among adolescents decreased with a significance value of p=0.008 (p<0.05). This result shows that in addition to e-comics, Widya Pramana is validated as worthy by experts in materials, languages, media, and potential users. It was also shown to be effective in increasing sexual knowledge and lowering adolescent early marriage intentions in trials.

The effectiveness of education through this e-comic is attributed to its content, namely sexual education based on the teachings of Serat Widya Pramana, which cover biological, psychological, and social aspects. Sexuality-based education, Serat Widya Pramana, aligns with the findings of (Lumban Gaol & Stevanus, 2019), who emphasize that thorough sexuality education should include all three dimensions. It is also reinforced by research by (Chibuye & Kumatongo, 2022), which shows that comprehensive sexuality education has a significant role in preventing early marriage by providing comprehensive information about sexuality, reproductive rights, and healthy relationships. This understanding equips adolescents to make wiser decisions regarding relationships, while avoiding social pressure to marry at a young age. In addition, comprehensive sexuality education helps them understand the negative consequences of early marriage, such as unplanned pregnancies and health risks, so they are encouraged to postpone marriage until they reach physical and emotional maturity.

The results of this study are also in line with research by (Handika, 2022), who develops the media e-comic based on local wisdom, Begawi Pepadun, on reproductive system material for Grade XI high school students. The developed e-comic is feasible to use after receiving positive responses from both educators and students. Likewise, research by (Wulandari et al., 2020) shows that comic media has an influence in increasing adolescents' knowledge and attitudes about the impact of premarital sex. Comic media can be used to overcome boredom when receiving material. Comics with color illustrations can appeal to all students of all ages (Handika, 2022).

Comics are a visual communication medium that is more than just light-hearted and entertaining stories; they can also be applied as an educational tool and convey information effectively and efficiently (Apriani, 2023). Rapid technological advancements increase the ease of accessibility in comics. Comics no longer need to be printed and can be read anywhere and anytime. Serat Widya Pramana Sexual Education e-comic can be accessed through the website link, so users do not need to download any application on their devices. It can also be accessed and enjoyed from various devices, including mobile phones, Tablets, laptops, or computers, as long as it is connected to the internet.

In addition to the various advantages above, this study has several limitations. First, this study only applies three of the five stages of the ADDIE model, namely Analysis, Design, and Development. Further research is recommended to apply all stages of the ADDIE model to obtain more comprehensive and valid results. Second, design, communication, and visual experts provide input and suggestions to extend the storyline and add dramaturgy in each episode's subsequent comic development. This aspect also aligns with suggestions and input from potential users to extend the story. Third, it was found that one of the students had a higher post-test score compared to the pre-test. The observation results found that students were not serious about working on the scale and often joked with other students. This result can be something that needs to be considered for future research.

This article is part of a research project conducted under the Merdeka Belajar Kampus Merdeka (MBKM) Program at Universitas Sebelas Maret, funded by the non-State Budget (non-APBN) of Universitas Sebelas Maret in 2024, with the contract number: 1226/UN27/HK/2024