Are you harboring a/an alien, angel, anthropomorphic animal, brainwashed test subject, clone, demon, goddess/god, inter-dimensional traveler, living weapon, mermaid, superbeing or synthetic human bishojo/bishonen?
Do you need to Hand Wave their bizarre behavior?
Do you live in Japan or in an area of predominantly Japanese culture?
Then do we have the excuse for you!
Yes, an unfortunate bit of [...] [tvtropes.org]