Warning. This page contains mention of suicide.
Jules

Not a zombie, but also not a ghost; still part human and definitely not alive... She attempted suicide in a subway but instead of finding peace, she found herself in a liminal existence between life and death. After this incident, she got chained to the train she attempted suicide on and got assigned as the guardian of it. When she was alive, she struggled with her mental health, frequently feeling isolated and at a loss for support; the people around her felt empty, their relationships superficial. With her goals out of sight, her identity a mess, and her purpose blurry, she marked her suicide date for a week before her 21st birthday.

Now, she's detached from most things, acting like a free spirit, losing herself in mundane things and trying her best as a guardian for the entrance to Morte Realm. The passengers seem to be fond of her, but they only see her as some sort of mascot to the train. The only ones who see her true value and strength are Dalvan, Razru and Lillium.