Initially ordinary, Wataru displays average academics but excels in sports like baseball, soccer, and roller skating, traits aiding his selection. His quest involves ascending Soukaizan's multi-tiered structure, defeating tyrannical rulers on each level to restore color to the monochrome rainbow governing the realm's balance. He forges critical alliances, including with Himiko Shinobibe, the seven-year-old leader of the Shinobibe Ninja Clan, and Shibaraku Tsurugibe, a master swordsman mentor. These bonds highlight his deep loyalty and role as an emotional anchor for companions like Toraoh and Kurama Wataribe.

Wataru's personality centers on altruism and an all-loving hero mentality, though he grapples with insecurities about his savior status, admitting in *The Never-Ending Tale of Time* OVA that duty rather than innate confidence drives him. His development includes vulnerability: memory loss in *Super Mashin Hero Wataru* leads to uncharacteristic delinquency until reuniting with Ryujinmaru restores his identity. He also experiences unstoppable rage in episode 43 of *Super* when deceived about Toraoh's death, causing destructive consequences. While typically conflict-averse, he demonstrates adaptability through cross-dressing disguises in multiple episodes to infiltrate enemy territories.

Distinct traits include a habitual nose-rubbing tic, a fear of snakes, and a dislike of vegetables like konjac, carrots, and onions. His physical specifications note a height of 131 cm and weight of 27 kg. In the 2020 web animation *The Seven Spirits of Ryujinmaru*, he reunites with Ryujinmaru in a fragmented Soukaizan to confront new threats and restore the realm. Across all media, his core identity remains a child balancing innocence with the weight of prophecy, driven by compassion and resilience against cosmic threats.