Toshishita no Senpai

Nanasawa is a 25-year-old woman who can't let go of her crush for her high school senpai Sedo. Suddenly, she jumps back in time to 10 years ago! There, Nanasawa finds Sedo back in the second year of high school. Now in order to get together with the girl she loves, Nanasawa's "redo life" begins! A time-slip yuri ecchi comedy!
(Source: Yanmaga Web, translated)