A group of university students who belong to the same tennis club, Shino Yuta, Sakurada Miki, Sasaki Rinka, Takano Natsu, Fueki Mana, Tachibana Satsuki and Sakurada Wataru, go on a graduation trip to a cottage in the mountains in winter. Although the seven members seem to be good friends, each of them actually has secrets which they cannot tell anyone about; hidden feelings of love and jealousy. Yuta, the cool and brilliant president of the club, is attracted to the sociable and trusting Miki, and intends to tell her about his feelings on this trip, but things do not work out the way he wants. Miki is dating Yuta's good friend, the free-spirited Natsu and is so into him that she is blind to her surroundings. The seven friends have conflicting positions and when love starts to go down the tubes, a murder occurs like a bolt from the blue. Amid the fear and doubt, hidden emotions begin to come into the open through exchanges which probe each other's intentions.