My name is Yusuke Kihara.
Since college began I've been the lover to my aunt Azusa.
But home life with me and my mom is the same as ever.

Then one day, my mom Sayaka
suddenly announced her plans to remarry.

Remarry!? I can't forgive that!
I absolutely can't bear the thought!

If she needs companionship so badly I can give it.
Thus I became my mother's lover too.

[From DLsite English]