Prince of Tennis: Blue Skies and the Sea

The author's made some of the characters out of character. If you can't keep reading, just drop it. There are plenty of good books, so pick another.

Kaito is an ordinary high school student who transfers to Kanagawa because of his parents' work.

During lunch break on his first day of school, he takes his lunchbox to eat on the rooftop, only to find the door locked.

“You want to get in too?”

A gentle voice comes from behind him. Kaito turns and sees a blue-purple-haired boy holding a key.

“Want to come in together?” Yukimura Seiichi smiles as he opens the door. “This really is a great place to have lunch.”