Sai X Ai

From Chibi Manga:
She loved a teacher. But that kind of love is forbidden! Still she kept on loving him, and didn’t care about it.
One day, she met a boy in white clothes in the greenhouse of the school. She saw his kind eyes and she smelled the odor of wood coming from him. For the first time, Tsugumi felt her heart beating for someone.
But after that encounter she understood that this guy was her teacher…!!