Mari has concerns for her classmate, Saegusa. Saegusa has been hanging out with a boy named Tatsuya, and she wants to make sure Saegusa is dandy. She invited herself over one day, only to be welcomed by Saegusa dressed as a cat and sucking on Tatsuya's dick like it's the most delicious thing in the whole wide world. How will Mari's sensitive sense of smell react to this?
Saegusa, a girl that's willing to show her underclassman what it means to take charges is out to prove to Tatsuya that she's the senior! However, her status as senior matters very little when it comes to Tatsuya.