To You, Running Through Spring Dreams

Mei, now in her first year of high school, reunites with her senior from her senior days, Masumi, and is invited to be the manager of the baseball team. Mei has secretly had feelings for Masumi, who she has admired since middle school. However, whether Masumi knows about Mei's feelings or not, he has been acting indifferent to everything outside of baseball... Just as Mei is trying to forget her unrequited love, a baseball team member named Shiba Motohiko appears before her, claiming to know her from middle school.

(Source: Natalie, translated)