>>55865517After losing the war, the Japanese mentality had to be restructured, they were no longer the warrior nation that would die for their god emperor, the economy collapsed and instead of focusing on looking for a strong man, the Japanese woman looked for a man with a livelihood, the country refocused their remaining resources on industry and technology, abandoning the army, as well as encouraging a philosophy focused on work, here the figure of the salaryman was born, now this was the standard of an attractive man, someone who does not waste his time exercising or looking good, he only dedicates himself to his work. As the country's economy stabilized, entertainment media dedicated to women began to emerge, such as boy bands and bars with hosts where men with soft features were favored.
Currently, the ideal man for a Japanese woman must balance between having a good job or being a good student in the case of minors and having a neat, not ostentatious appearance, while muscular men are seen as selfish by society or, in worse case, as part of the gay community.
Also answering the question, anime characters are mostly created so that the target audience can identify with them, in this case Japanese teenagers. This is why many animes have a twink boy as MC or in the case of shoujos a Plain Jane as the protagonist.
t.hafu