4As Daikichi continues to juggle work with raising a teenager, Rin struggles with the relationship between her and Kouki, her childhood friend. The last ten years have brought about a variety of changes to their friendship-some subtle, some not so. Kouki may always have been head over heels for Rin, but the choices he's made in the past seem to have put a wedge between them. And when a scorned ex sets her sights anew on Rin as the object of her rage, the tricks up this girl's sleeve threaten to nip Kouki's potential romance with Rin in the bud for good. As Rin's sixteenth birthday approaches, will there be cause for celebration? Or will Daikichi have a crisis of the heart on his hands?