Karin and her neighbors Sakumi and Tatsumi (brothers) have known each other forever and are best friends. When Sakumi returns home from college, Karin couldn't be happier, however she can tell he has changed, andhas become more mature. He feels farther away from her, which upsets her because she has a huge crush on him. Meanwhile, Tatsumi, who is in the same grade as Karin has feelings for her. Sakumi, after returning home from college, realizes how much he missed Karin, and begins to see how special she is. Karin, Tatsumi, and Sakumi form a love triangle...