During the rainy season, a young man is about to take someone else's umbrella from the stand outside a convenience store. As he reaches for it, he feels an unsettling gaze upon him. Looking up through the rain, he sees a mysterious fish hanging from a string, staring at him. The fish does not speak, does not move, and does not change its expression. This creature is named Pisu-chan.

Pisu-chan is a mysterious fish that never moves at all, yet it livens up the convenience store where it resides. The story unfolds as a laid back and surreal comedy centered on Pisu chan and the small world of the store. Surrounding the unmoving fish are a mischievous store manager, mysterious bugs who are surprisingly good at their jobs, and innocent but merciless children who come to play. The narrative follows the quiet, bizarre daily life at the convenience store, where Pisu chan observes everything without ever reacting, creating a unique atmosphere of absurdist humor. The story originated as a web comic released on social media platforms starting in June 2023.