Level E

 Hundreds of aliens inhabit our Earth today. Some friendly, some belligerent - some are here for research purposes while others came for the sake of committing crime. It is only us humans who have yet to realize their existence.

One day, a hell of a troublemaker arrives on our planet. Though he is regarded as the smartest man in the universe, he has a major flaw in his personality - he is always causing trouble to bide his time.

(Source: Crunchyroll)