CONAN: We are enemies and can never be together.
Aaron: I just want to be with you.
CONAN: We're ten years apart.
Aaron: Then you should never change back.
CONAN: Impossible!
Aaron: Why?
Conan: Because my favorite has always been Lan.
Aaron: Then I'll kill her!
CONAN: Don't even think about it!
Why? What she can do for you, I can do for you, and I can protect you, but why do you always like her.
Because you are a devil trapped in hell, and he is an angel who lives in heaven forever. The distance of ten years is like the distance of tens of millions of years, and we can never be together.
The heroine is the daughter of Gin and Belmode, non-time travel, name: Kurosawa Aaron (taken from Jack the Ripper's real name: Aaron Kosminsky), codename: Martini