Saitama in One Punch Superman was a very powerful hero, but the reason he couldn't become an S-class hero was because of some problems with his personality and motivation.
Saitama was a very self-centered person. She had a very strong pursuit of her own strength, even at the expense of the interests of others. This kind of self-seeking performance often made him do some selfish actions, such as attacking other heroes or ignoring the safety of others in order to protect himself.
Saitama's personality also caused him to be unclear about some moral values. He did not care about the feelings of the other heroes. He only cared about whether he could become stronger. This kind of attitude often caused problems in teamwork because he did not understand the importance of teamwork.
In summary, Saitama's personality and motives were the main reasons why he could not become an S-class hero.
Another plot could involve Saitama using his new S - Class status to reform the hero system. He might see all the flaws in it, like how some heroes are more concerned with fame than actually saving people. So, he starts making changes from the inside. He could introduce new training methods or even a new ranking system that focuses more on a hero's selfless deeds rather than just their power level.
Genos would probably be even more in awe of Saitama. He already idolizes him, but with Saitama being S - Class, Genos might see him as even more untouchable. He could become more protective of Saitama's new status, trying to fend off any detractors or those who might try to take advantage of Saitama.
Saitama's origin story is quite interesting. He was an ordinary man who was frustrated with his job - hunting and general lack of success in life. He decided to become a hero just for fun. He started a very intense training regime that included 100 push - ups, 100 sit - ups, 100 squats and a 10 - kilometer run every day. Through this extreme and consistent training, he gradually became so powerful that he could defeat any opponent with a single punch.
Fan Xian's class was the homeroom teacher's. Fan Xian was compared to the class teacher, fighting wits and courage with the students. This scene reminded people of the interactions with the class teacher in school. Although the search results did not explain in detail what Fan Xian's class smell was, it could be inferred that Fan Xian's class smell was similar to the sense of responsibility, authority, and management ability of a class teacher.
Saitama is a very powerful hero in the One Punch Man universe. He can defeat any opponent with just one punch. He has a simple appearance and a somewhat laid - back personality.
One way is to explore his life before he became a hero. Maybe he had a normal job and was constantly frustrated with the mundanity of it. This could have been the catalyst for his intense training.
Saitama's rank in the web comic is sort of unconventional. His strength is off the charts, making it difficult to slot him into a specific rank. You could say he's in a league of his own, far above the typical rankings.