The story of Lesson XX has a sweet feel to it. It revolves around two boys, Shizuka and Sakura who are friends at a coed boarding school. One day, Shizuka happens to notice Sakura’s sheer beauty when he dives in to take a hit from a baseball. After some mixed up thoughts of who Sakura likes, Shizuka tells him he wishes to kiss him as a joke. But Sakura doesn’t care; he still insists that the two kiss under the starry sky. After this incident, Shizuka thinks it’s best for the two to be away from each other, so as to sort out their thoughts and real feelings.