The Hinako Mori Mori becomes a cute little devil! One day, her older sister Kokoro shows off her boyfriend who came to visit her at home to Hinatako, who is single. Hinatako's jealousy is ignited and she can't control her urges and seduces her sister's boyfriend with her sweet voice. Hinatako turns into a sweet kissing monster and her boyfriend gets excited! He has sex with her without her sister knowing.