Responses
Manga or book? If it's a manga the only one I can think of is "Kokoro O Korosu Houhou" but I don't really know if it can be defined as a happy ending per say.
Sakura gari, suicidal mc with plot twist..not your preferred ending but its amazing.
raising a bat
Blue Lust
I would like a well written story with the m.c being suicidal, with preferably a happy ending, please and thanks!