Yui is being trained to swallow cum by a fuck buddy who already has a girlfriend. She knows he is using her, but drinking the semen his girlfriend does not get is how she reassures herself that she is special—even though what she truly wants is for him to cum inside her. When her childhood friend Dai confesses his love, she sleeps with him in despair and swallows his cum. Dai then gives her the creampie her fuck buddy always denied her, pushing their painful love triangle in a new direction.