Is there any gay character here?

None. In Ao3, the most shipped pair are Narumi/Hoshina and Furuhashi/Ichikawa... I had to say, Hoshina as an omega works so well in fanfics.. hahaha.
Still, I like that Kn8 doesnt have romance..

What is ao3

AO3 or Archive of Our Own is a fanfic website for different fandoms of different media.. whether it be a tv show, movie, foreign drama, idol group, manga, anime, etc.. It can be quite intimidating to navigate at the beginning but its filters are the best if you are looking for something specific.