Reiya, Taiyo, and Momoha are three good friends from the same university. Taiyo and Momo are dating, but when they get into a fight over something trivial, Reiya sees an opportunity and makes a move on Momo. Momo falls into pleasure from the intense sex that is different from Taiyo's... she begs him to "Cum inside me... please..." When Taiyo returns, he is shocked to see something...