Promising pitcher Megumi and catcher Nagisa form an unbeatable battery during their high school baseball days, bonding over their shared determination to reach Koshien. Megumi falls in love with Nagisa at first sight, and his single-minded devotion to both baseball and Nagisa drives their partnership. However, during their final summer tournament, Nagisa injures his shoulder, effectively ending his baseball career. After graduation, Nagisa enrolls in a university, determined to move on from the sport. Megumi, unwilling to let go of Nagisa, turns down a professional baseball offer and follows him to the same university. Nagisa tries to distance himself, struggling with the painful reminder of what he lost and the feeling that without baseball he has nothing to offer Megumi. Yet he cannot fully release his attachment to the pitcher who was once his partner. The story traces their push-and-pull as former teammates navigate lingering feelings, jealousy, and the question of whether their bond can survive outside the diamond. A past arc explores their first meeting and the early days of their relationship, while a side story follows them as working adults—Megumi now a pro player and Nagisa working as a trainer—where unresolved insecurities resurface when Nagisa's older brother, also a pitcher, joins Megumi's team.