Sayonara Zetsubo Sensei

Sayonara Zetsubō Sensei revolves around a very pessimistic high school teacher named Nozomu Itoshiki who, at the very beginning of the series, tries to hang himself on a sakura tree. Despite this effort of self-destruction, he is saved by an extremely optimistic girl known only as Kafuka Fūra (it should be noted, however, that in her effort to save his life, she almost kills him). She explains to him that it is simply unforgivable to hang himself on such a nice day, especially in front of such beautiful trees. She decides to nickname Nozomu "Pink Supervisor" (桃色係長, Momoiro Kakarichō?), and offers to pay him fifty yen to call him by that nickname. After having enough of the strange girl, Nozomu bolts to the school and starts his homeroom class, but the attempt to escape was in vain as he finds that the girl is one of his students.