The daughter of Nana Komatsu. Not much known about her, and she makes only a few appearances later in the series. When she appears, she is six years old (presumably showing the future outlook of the story). During her pregnancy, Hachi and Takumi unofficially called her "Sachiko". It is not known if she is truly Takumi's or Nobu's child, but bears a striking resemblance to Takumi, with black hair and hazel eyes. She is revealed to have a crush on Shin, though his reciprocation (or even his knowledge of her feelings) is unlikely. Her name, Satsuki, was chosen by Ren at the request of Hachi, who was unable to think up any name other than "Sachiko". It is indicated that Ren may be her older brother as once her mother had asked whether she would give her Valentine chocolates to "older brother".