Yuujo Mijikashi Koi Seyo Inma!

Synopsis

Tomonori, an unmarried salaryman, was living an ordinary life, until one day when his friend Nozomu suddenly became a succubus! Though Tomonori doesn't know how to return Nozomu back to his original form, he decides to let Nozomu live with him for the time being. However, Nozomu is ridiculously seductive and it's incredibly difficult for Tomonori to resist their charm! (Source: Kadokawa, translated)