Tatewaki Naito enters Fukuhara High School as Chrono Shindou's solitary and serious rival. He possesses an intense focus on strength and victory in Vanguard fights, wielding the direct and overwhelming power of the Narukami clan, known for retiring opponent's rear-guards.

Driven by a past where he valued only strength and winning, Naito walked a solitary path, seeking to prove himself through a misunderstood concept of true power. He identifies Chrono as his primary rival due to Chrono's unique fighting style and potential. Naito's formidable skills and relentless drive to defeat strong opponents, especially Chrono, mark his early encounters. He initially dismisses teamwork and camaraderie, believing solely in individual strength.

Participation in the High School Vanguard Championship with Fukuhara High forces Naito to interact with teammates like Mamoru Anjou and Kazuma Shouji. Though initially resistant and critical, the team dynamics and shared objectives challenge his isolationist stance. Battling powerful tournament foes, including teams like the Dragon Empire branch school, pushes him to adapt and refine his strategies.

A pivotal confrontation with figures from his past, who embody the ruthless pursuit of power he once followed, forces Naito to re-evaluate his definition of strength. He begins to understand that power encompasses more than individual victory, involving trust, protecting others, and fighting alongside comrades.

His rivalry with Chrono evolves from pure antagonism to a complex relationship built on mutual respect. While remaining fiercely competitive and driven to surpass Chrono, Naito acknowledges Chrono's growth and influence. He gradually starts appreciating the bonds forged through Vanguard and the Fukuhara team, slowly integrating himself into the group while retaining his characteristic intensity and focus on becoming stronger.