The young master of the prestigious Orca Weir, returns home after three years on the battlefield. Orca is a top predator who prefers slaughter over peace and conflict over comfort, finding the family mansion in Rosselphia utterly boring.

Appearing before Orca is the trivial and foolish servant, Nia. As a Goldfish Beastkin (specifically, a pearlscale), Nia is tormented and scolded by the other servants due to his frail, clumsy, and forgetful nature. However, his poor memory allows him to quickly forget the pain.

One night, starving, Nia sneaks out to the mansion's lake to eat water plants and marsh snails because he can't sleep from hunger.

It is there that he runs into Orca, who had also snuck out to skinny-dip and, being bored, was considering "going to take a look" at what the careless servant was doing.

Upon being caught, Nia pleads: "Young Master, I was wrong... I beg you, please save me..."

For Orca, who is unused to peace, the sight of Nia—"someone so insignificant and weak—struggling to live" is annoying and unsettling. Although he tries to ignore him, he can't stop his attention from constantly drifting towards the small and fragile Nia.

Suddenly, the once-boring mansion begins to fill with an unknown tremor or emotion for Orca.