Following her father's departure for overseas work, Konatsu Amano relocates to Iyo-Nagahama to stay with her aunt. En route to her aunt's residence, she stumbles into the aquarium open house at her new high school, where she crosses paths with the charming upperclassman, Koyuki Honami. Their chance encounters spark a mutual fascination. Eager to draw closer to Koyuki, Konatsu decides to join the aquarium club, previously a solo venture for Koyuki. Both girls share a sense of isolation, kindness, thoughtfulness, and a hint of reticence and stubbornness, complicating their budding connection. As they grapple with their unspoken emotions, Konatsu and Koyuki must unravel the depths of their bond and confront their innermost selves. Will they persist in their solitude, or will they muster the bravery to confront their feelings and embrace a shared future?