Watashitachi no Shiawase na Jikan, Orange Recommendations
These 2 wonderful manga share themes of romance, tragedy, and regret. Their story lines are rather deep as they involve death in some way, and many emotions are evoked in the reader. In Orange, the main character attempts to resolve her regrets regarding a close friend as directed by her future self in a letter. WnSnJ's protagonists, a suicidal pianist & scarred murderer, connect and attempt to make peace with their darkest secrets. Both stories' tones, characters, and artwork are brilliantly executed.
Both of these manga deal with depression and suicide.
Both develop relationships that lead them to wanting to live and shows how even when you have nothing to live for there are still people who love you.
BOTH MADE ME CRY