Haru reminisces about his youth, from his parents' struggles with poverty that led to trouble with the yakuza, to his meeting a dolphin that inspired his fascination with the sea, and finally to his exploration of the ruins of his city, now underwater because of climate change, which led him to become a test diver for early Meta-Real experiments.
のどかな午後。静かに時の過ぎ行く中、波留とミナモは散歩に出かける。その最中、波留は自らの少年時代、東京で生まれ育ったこと、そして失われた故郷の姿と、第二の故郷、唐津ではじめて海に潜ったときのことなどを思い返していく。自分がなぜ今もこうして海を求めるのか。その答えを波留は静かに見つめ直していくのであった。