Niyago balances an ordinary life as a Cat Town elementary student with his secret identity as the superhero Super Niyander. Chosen by the Cat Wizard for his caring, kind-hearted, and selfless nature, he embodies truthfulness and is well-loved, though his popularity draws rivals. While academically and athletically average as Niyago, his defining quality is an unwavering readiness to help anyone in need, even adversaries who ask for aid.

His transformation into Super Niyander brings distinct physical changes: his whiskers and tail vanish, and his eyes shift noticeably. As Super Niyander, he wields a magic sword, his true weapon, and adheres strictly to a moral code prioritizing assistance and peacekeeping over personal ambition.

Niyago's younger sister, Miko, initially unaware of his double life, deeply admires Super Niyander and wishes her brother possessed the hero's qualities. After discovering the truth, she persuades the reluctant Cat Wizard and eventually becomes Junior Niyander to support him. His closest companion is Pidori, a pterodactyl he raised from birth. Pidori acts as a vital partner, delivering Niyago's superhero costume and assisting in rescues, communicating solely through the sound "Pi," which Niyago understands.

Despite his heroic power, Niyago retains specific dislikes: an aversion to capsicums and caterpillars persists even after he transforms into Super Niyander.