Classmate Gal, Shiina Chiiri her tutor is Muroto Kouta. When she ends study, as a reward, it becomes a relation like sex friends that does sex acts other than insertion. Chiiri who was stood up from her boyfriend on Christmas day, she tells Kouta who was present that she did not feel like studying. A sad earnest Chiiri shedding tears, Kouta who is mad conveys one's love feelings. Chiiri who was hit by Kouta's feelings?