Houkago no Fujun by KAJIGAYA Michiru [Eng]

Plot: In a classroom after school, Sawaki of the Athletics club and Mizutani of the going home club practically almost never spoke to one another before then. Their relationship started by an intense kiss by Sawaki. In a locked-room infirmary, library, home, and school trip… They deepen their love timidly but passionately. A story about secret lovers that will move your heart endlessly!