Joshi Daisei ga Goukon de Onee-san ni Mochikaerareru Hanashi
Other names: About a College Girl Who Gets Picked Up at a Mixer by an Older Girl, 女子大生が合コンでお姉さんに持ち帰られる話
Author: Yukio Yuki
Artis: Yukio Yuki
College girl Kawada Rika gets roped into going to a mixer where she meets an older girl named Suda Natsuko and they are immediately enamored with each other.