Wakana Seito lives in blissful confusion. His father remarried to a beautiful young woman named Kada. Now he's gone and Kada has raised Seito on her own. Now he's a young man--with adolescent fantasies about his step-mother. But then his aunt, Kanna, is coming for a visit. Seito awakens from an afternoon nap and spies his mother in the shower. But his step-mother isn't upset at all to catch him spying on her--and she's very glad to see him--!

Note: Even though this manga is about mother and son there are no incest here because it is actually step-mother who loves her step-son. They are of course aren't blood related.