We Started a Threesome!! manga volume 1 features story and art by Katsu Aki.

Ria, Suisei, and Emito are childhood friends who fell in love with each other. Now they share a home as a married throuple! In the morning Ria and Suisei commute to work, and at night Emito cooks delicious meals he hopes they'll enjoy. Follow their daily lives as they face challenges, celebrate victories, and indulge in the more intimate side of marriage together. A story about polyamory by the creator of the famous married life manga Futari H (Manga Sutra)!