Middle school teacher Nobunaga has always been dreaming of such a gal game-like situation. However, the one who appeared before him was Kichou, a 14-year-old girl who proclaims herself as his wife. Appears to have arrived from the Sengoku era, she mistakes Nobunaga as Nobunaga Oda and urges him to conceive a child with her. Thus begins the age-difference love comedy between a gal game-loving teacher and a Sengoku era expert princess.

The romantic comedy's story begins when the pretty, mild-mannered student council president announces a new dress code regulation, "underwear is now banned."

Koe de Oshigoto! is a story about Aoyagi Kanna, a 16 year-old girl who was asked to become an erotic game voice actress on her 16th birthday by her 28 year-old sister at her ero-ge company. Can she do the job properly while she's still innocent and inexperienced?