There's a girl who attempts suicide but is saved by a boy and it turns to a love relationship almost like love at first sight. The boy ask the girl why she wants to die and she says she has thanatos illness. Basically people ruled by thanatos want death and those ruled by eros desire life and will to live. People with thanatos can see the grim reaper. Since the girl has thanatos the grim reaper is calling out to her and the boy gets jealous. She tries to attempt suicide again and it looks like she is just waiting for the boy to come and save her again. After a while she says no more so they break up and now the boy the boy doesn't want to live either. Now it flashes to where they are both at a rooftop and the girl finally smiles (both ready to jump off) they both jumped off happily and the boy died... the girl didn't because she never existed. The boy was the one with thanatos the whole time and the girl was his grim reaper.
Basically this is a summary from the novel called Temptation Of Thanatos and inspired by the song called Racing Into The Night by yoasobi.
