Level E

Level E (レベルE, Reberu Ī) is a comic science fiction manga series by Yoshihiro Togashi.

Level E was originally serialized in the Japanese Shueisha magazine Weekly Shōnen Jump from 1995 to 1997 for a total of 16 chapters. These chapters have since been collected into three volumes, as well as two magazine-style books. An anime adaptation of Level E was produced by Studio Pierrot and David Production and aired on TV Tokyo in early 2011.

Plot
Earth has been populated by thousands of aliens from all over the galaxy. While all the other aliens are aware of their presence, it is a secret only from the Earthlings. Baka, the prince of the planet Dogra, crash lands on Earth and loses his memory. He forcibly moves in with Yukitata Tsuitsui, a first year high school student who had just moved out on his own. The normal life he once knew is quickly pulled away as he becomes the target of the prince's torment.