Plot
Hinata Sunohara is an orphan and student who lives alone. He was summoned to a fantasy world and with his party defeated the Demon Lord who was threatening the land, but as soon as they did, he was sent back to Earth. He settles back into his life, but one day, his party member, the dark elf Mariabelle, teleports into his apartment completely naked. After getting her clothes, she explains that she is in love with him and wants to be with him forever. He lets her stay in his apartment and helps her adjust to Earth, but must cope with the fact that she is completely obsessed with him, constantly tries to seduce him, and becomes murderously jealous of any girl he interacts with like his classmate Sakura Mochida.
(Source: Wikipedia.org)