聖クロス女学院物語

At St. Cross Gakuen, a Catholic girls' middle school, each underclassman is mentored by exchanging letters with an upperclassman, her secret onee-sama. Best friends Hana and Nana are new first-year students, who encounter the beautiful student council president Shiori and vice president Mitsuki, and join the paranormal club started by their eyepatch-wearing classmate Kanon.