Futaba Ooki, who is originally from a big city, spends much of her days photographing her life on her phone. She gazes out over the huge expanse of sea after moving to a beach town and is instantly attracted by its unlimited possibilities. Unbeknownst to Futaba, Hikari Kohinata, a local diving enthusiast, notices her silent concentration. Hikari is captivated to Futaba's quiet and shy manner the next day when they are in the same class, and she fondly nicknames her Teko, establishing a sensitive bond.