Hideki's a decent guy overall and realises it's a bit perverted to have his girl persocom running around the place with no underwear. Unfortunately, inexperienced as Hideki is, buying female undergarments holds a great source of embarrassment for him. Hearing about the dilemma Shinbo offers Sumomo's services as navigator and generally being a source of common sense for Chii, in order for her to go and buy her own underwear. This sounds like a great idea at the time, but causes a seemingly infinite amount of worry during the day at prep school for Hideki.