The High School Girl Came to Buy Adult Toys.

Aya Mizuki, a high school girl working part-time at a used bookstore that also sells adult goods, one day encounters Yuki Kayano, a top student in her class, in the adult section. Yuki, who is highly regarded at school, is actually there to examine goods for "stress relief." The two girls, sharing a small secret, gradually deepen their relationship—a high school girl-meets-girl story that begins with an unexpected encounter.

Source: Comic Gardo, Translated