- This is the story of a high school girl named Mika (Yui Aragaki) who falls in love with her schoolmate Hiro (Haruma Miura). A summer romance started when Mika lost and retrieving her cell phone and begins to recieve calls from Hiroko. While their love becomes more intimate, Hiro leaves her without telling the reason. Despairingly, Mika stop herself from being in love again. Later, she meets a guy named Yu (Keisuke Koide) who attempts to make her happy. Mika opens her heart again and strat dating Yu. However, on the night of Christmas Eve, Mika discover the real reason why Hiro is gone...