Fujino Nikaidou

She's Akihito's Aunt, whom he has his first sexual relationship, once married but was left by her former husband dud to the inability to conceive.

She runs a bar where she is also the bartender.

She later on lives with Akihito upon being left by his wife for the latter's boss.
And she also forms one of Akihito's live in harem.

Among the harem, she is bisexual, and has a tendency to be wild in bed.