Tokyo Aliens

Akira Gunji has just started high school, and on the way home, he has a surprise encounter with an old lady who has tentacles spring from her back. It turns out she is a certain type of alien. Amidst the confusion, he meets his classmate Shou Tenkuubashi, who has come to catch her. A tale of extraterrestrial life set in Tokyo! (Source: Square Enix, translated)