He can only stay human for an hour each day but it slowly increases as he levels up.
I cried at the climax because of how resolute he was in confronting the tragedy. The ending is very heartwarming so you won't feel that sad by the end of the one-shot. A very sweet romance in which you can truly tell how the characters feel from their actions.
That twist got me so hard. Didn't expect it at all. I thought it was over with the first but the real twist made me laugh so loud.