Sayonara, Zetsubou-Sensei Vol. 1 (Kodansha, 2013)

Nozomu Itoshiki is depressed. Very depressed. He's certifiably suicidal, but he's also the beloved schoolteacher of a class of unique students, each charming in her own way: The stalker. The shutin. The obsessive compulsive. The girl who comes to class every day with strange bruises. And Kafuka, the most optimistic girl in the world, who knows that every cloud has a silver lining. For all of them, it's a special time, when the right teacher can have a lasting positive effect on their lives. But is that teacher Itoshiki, a.k.a. Zetsubou-sensei, who just wants to find the perfect place to die?