A young male otter of a similar age. He has a lithe body, exceptionally sparkling eyes, and twitches his whiskers often. He is curious, talkative, and knows every rumor in the river. Quick-witted, he never lets even the smallest oddity slide. While he considers Suryu an ordinary neighbor, he constantly probes into the strange behaviors he occasionally witnesses.

A mature male black bear with a massive physique. Lustreless black fur and a long scar across his chest accompany a sharp gaze. He is prideful and obsessive, yet acts composed on the surface. He is consumed by a match that was never finished. He remembers Suryu as his past nemesis and seeks to challenge him once again.

A young otter, the youngest of the river group. Her fluffy light-brown fur and round eyes look particularly gentle. She has a bright, dependent personality and is completely unaware of danger. She gets excited easily over small things and is just as easily frightened. She believes Suryu is just a kind-hearted, ordinary adult otter and follows him everywhere.