Beneath Tokyo, a hidden city waits-built from rusted pipes, scavenged glass, and the fragile trust of its rodent inhabitants.
Nibanbashi is a place of uneasy peace where rats, squirrels, and hamsters share tunnels under the watchful rule of Emperor Nabu. But far to the north, the gerbil stronghold of Grotubil beats its war drums, and further still lies The Uens-a near-mythical home to the godlike capybaras.
Rosco, a humble stew seller with no taste for politics or adventure, only wants to keep his father Blook safe and the pot simmering. Yet the collapse of a vital bridge, the shocking murder of a young rat at the city's beloved festival, and whispers of old enemies set the undercity on edge. When tragedy strikes his own life, Rosco is pulled into a web of suspicion, factional tension, and secrets that threaten to unravel Nibanbashi itself.
From the bustle of the Crescent Market to the shadowed mouths of forbidden tunnels, Rosco's path will cross with sharp-tongued strangers, hidden allies, and dangers older than the city itself. To survive, he must navigate a world where loyalty is a gamble, peace is a performance, and the truth is as dangerous as any blade.
Rosco is a richly imagined tale of grief, survival, and the flickers of hope that persist even in the deepest dark.