Recently, Rino's son's best friend, Kazuya, has been coming to visit her house frequently. Rino sees Kazuya as a polite, serious and reliable person. Unlike her son, Kazuya is well-liked by everyone, and Rino is pleased with him and starts treating him like her own son. However, Kazuya has another reason for coming to visit. He is Kokoro to the beautiful and stylish Rino. Kazuya fell in love at first sight the moment they first met, and every time he sees Rino, he secretly harbors feelings for her. And a casual remark from Rino makes him think wicked thoughts...