In the anime she's just doing it because she believes it's what an angel should do, in the manga it's originally because Kotarou is the reincarnation of his granduncle Claudia schiffer early sex video, the boy she loved who commited suicide.
Later, Peter offers to become Tucker's agent to get him famous, but Tom refuses until an inane news story makes him reconsider.
She constantly tries to drag them places and get them to enjoy life.
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And that makes sense…how, exactly?
Fenchurch in So Long, and Thanks for All the Fishalthough, really, she's probably the only woman on Earth weird enough to fall in love with Arthur Dent.