Fun facts about each of these protagonists
Kyoya Fullbuster (Spade Amongst Clovers):Despite what happened after Spade Kingdom, his magic power was so high that even after the timeskip, he is still leagues above certain magic knights.
Izayoi Heiwajima (When Fists Fly):Originally, he was suppose to take Mikey's place during the Tenjiku arc and prove that Toman can still fight without Mikey and that he's more than just a substitute. But since a certain incident never happened, this situation never came to be
Nagisa Tomioka (Chained Soldier and Still Waters):Despite him and Yuuki being best friends, Yuuki thinks it's scary how quickly Nagisa can adapt to certain situations that would scare a normal human
Shiki Koritsu (Sanity Versus Instinct):His relationship with Fushiguro Toji was based off the twisted relationship that Isagi and Rin have in Blue Lock
Ji-hyeon Kwak (Lookism:The Snake Who Hid His Fangs):Despite being part of the 2nd Generation, people have a tough time measuring his strength since hiding it makes it easier for him to use his fighting style which revolves around using counters