4 books in series

Koibana! Koiseyo Hanabi

Koibana! Koiseyo Hanabi is a 4-book series with 4 primary works first released in 2007 with contributions by Nagamu Nanaji.

コイバナ!恋せよ花火 1
コイバナ!恋せよ花火 2
コイバナ!恋せよ花火 3
Koibana! Koiseyo Hanabi Volume 10