Refrain Blue

Refrain Blue unfolds during a summer trip to the beach, where Matsunaga Yoshihiro supervises a group of high-school students grappling with their own personal challenges. The atmosphere takes a somber turn when he discovers Morisawa Nao, a student haunted by her past, attempting to take her own life. Having lost her fiancé in a tragic plane crash during the same trip the previous year, Nao's pain is palpable. As she and Yoshihiro begin to connect, it becomes clear that he too carries the weight of unresolved grief.

Amidst their shared sorrow, a mysterious girl known as the "Umi Warabe" appears at pivotal moments, suggesting a deeper connection to their journeys of healing. As they navigate their intertwined paths, both Yoshihiro and Nao must confront their pasts and find a way to move forward, leading them toward unexpected revelations and a chance at renewal.