Neet Kunoichi to Naze ka Dousei Hajimemashita

Follows Tsukasa, a normal salaryman who is attacked one night by demons, and is saved by a genius kunoichi named Shizuri. In her off time though, Shizuri is a lazy otaku NEET. Tsukasa and Shizuri end up living together, with Tsukasa using his homemaking skills to pamper Shizuri as she continues to serve as his bodyguard.