Yui Yamada, a high school student who enjoys gardening and plants, begins dating Tomoka Kase, the star of her school's track team. Yui is shy, girly, and has never had a boyfriend. Tomoka, on the other hand, is vibrant, tomboyish, and well-liked by her peers. Despite their many differences, they try to understand and encourage one another while enjoying the rush of excitement that comes with first love. Asagao to Kase-san is a touching story about two girls struggling with their growing feelings for each other, as well as other issues that plague maidens in love.