The High School Life of Kazuya Sato

Kazuya Sato is thought as an asshole by mostly everyone. He actually hates the 'Youth filled with genuine friendship and love' delusion that all teens in Japan are infatuated with, so he thinks of it as a plus. He also trained his body and mind quite a bit because of his chunni days. But because of living in a standard school life light novelish world, he can't live the loner life he desires.
WARNING: late romance and harem, no fan service, hopefully no rom-com base for romantic feelings (outlandish shit like; I saw him only once in my life but my heart fell for him or he protected me from bullies during elementary and we never talked again, I am in love with him), there is bromance and not all males in the novel are mobs or extras that don't matter in the story(no homo)