HBAD-505 Sister NTR My favorite guy was stolen by my sister

Film Introduction

Mamiko lives in an apartment with her older sister Kanna, who lives in Tokyo, to attend university in Tokyo. She is also on good terms with Mamiko's boyfriend Takashi, and she seemed to be watching over them, but she was secretly aiming for Takashi. She then "traps" her Takashi and calls her out for her own libido treatment, but Takashi can't stand the guilt towards Mamiko...