A young lady named Shirakawa Hotaru has long harbored feelings for Inami Ken. Eventually, she mustered the courage to express her love to him. Afterward, they became a happy couple until one summer when Ken encountered Tobise Tomoe, who is also Hotaru's best friend. This new acquaintance appears to possess an alluring charm of her own. Now, Ken faces a difficult decision: whether to remain loyal to Shirakawa Hotaru or pursue a relationship with Tobise Tomoe. If he chooses the latter, he risks losing both women.