As seasons have passed, Mizuho Nishino's adolescence has been full of ups and downs. With Christmas approaching, she intends to celebrate the special event with all of her four childhood friends: Kizuki Hazawa, Shin Kashiwagi, Airu Izumi, and Shuugo Hoshikawa. However, Kizuki makes the first move when he declares that he wants to spend the time alone with Mizuho. Although hesitant at first, Mizuho ends up confiding in him and declares Kizuki to be her boyfriend!

The news about Mizuho and Kizuki spreads quickly and brings forth Shin and Airu, who have had a difficult time accepting their feelings for the one they love. With the friend group faced with a delicate situation they have never confronted before, only time will tell if the new romance and old friendships can survive.