The father and son Yuki and Haru who's not connected by blood. Yuki, despite being an Omega has a body that doesn't get heats, is living peacefully with Haru who's an Alpha.... But, on Haru's 18th birthday he suddenly kissed Yuki, and because of this Yuki's body started to change..!? A cool and young Alpha and an Older Omega who don't have heats. A very wholehearted lovestory begins.