Goodbye, Mr. Despair (2007)

Nozomu Itoshiki is a high school teacher who always looks on the negative side of life, constantly left in despair from the troublesome issues society presents. He constantly tries to kill himself to free himself from this cruel world, but is unable to do so because of his class of students, many of whom are more bizarre than he is. There is Chiru who needs to organize everything perfectly, the mute but abusive Meru, Matoi who loves stalking people, and a host of other cute but crazy students the most frightening of which is the optimistic but oblivious Kafuka, whose enthusiasm is over-the-top and lethal to anyone she meets. With all the antics his students carry on, can Nozomu ever manage to find something good in life?