When Hideki Motosuwa leaves his apartment and accidentally forgets his wallet, Chii takes the wallet and follows him, leaving Sumomo and Kotoko alone in the apartment. It doesn’t take long time until Sumomo discovers that Chii forgot her panties, so Sumomo and Kotoko sets out on an adventurous trip to return the panties to Chii. <br><br> (Source: Anime News Network)