A Summer-Colored Memorial

Two years have passed since graduation and Utsumi and Matsuri meet again during a middle school reunion. Utsumi, who dyed his hair back to his original color, seems different than before. Was if because of Matsuri's nagging that he changed? Even so, Matsuri realizes that her feelings towards him haven't changed. But she soon learns that the one who actually changed him was a girl named Sayaka, Are first loves sweet poisons?