In the Kijima-kun series:

Volume 1 - Omae no Kawaii Kijima-kun!
Tachibana Sousuke is a handsome honours student who runs into a spot of bad luck one day: he loses his glasses, then his wallet, and to top it all off, almost misses out on lunch while blundering about half-blind. A guy he bumps into in the cafeteria helps him out, but since Tachibana can't see him clearly and the kid runs off before he can ask a name, he's forced to inquire after him from a classmate, who names his saviour as "Kijima."

Thinking of the kind, cute blond from another class, Tachibana begins to write the other boy erotic letters and leave them in his shoe locker. But a misunderstanding about kanji readings results in him instead slipping the increasingly lewd missives into the locker belonging to the school's "cursed black cat," Kijima Subaru...

Extra: Kenen Love Battle
A story about two businessmen who appear to be rivals on the surface but are actually lovers.