Story of Isamu Udai - A Haikyuu Fanfiction

This is a haikyuu fanfiction, were the main character isn't Hinata. The main character is Isamu Udai, the younger brother of the small giant. It follows the main anime story, and I'll try to keep the characters as cannon as possible.
There will be cursing, if there's any other warnings, I'll put them in the beginning of the chapter.