Isamu serves as the deuteragonist in the Zo Zo Zombie! WebShow, appearing as Zo Zo Zombie's steadfast human friend throughout nearly every episode. He actively partners with Zo Zo on adventures, frequently involving well-intentioned efforts that spiral into chaos, forming the core dynamic of their interactions.

Beyond the webseries, Isamu features as the main protagonist alongside Zo Zo Zombie in "The Curse," a Roblox story game inspired by the Zo Zo Zombie! universe, further exploring their collaborative relationship.

Isamu engages in numerous episodic scenarios showcasing his role. He experiences mishaps requiring Zo Zo's aid, like getting trapped in a bathroom stall needing urgent toilet paper delivery. He tackles missions alongside Zo Zo Zombie, such as stopping a tuna thief, navigating a runaway Zombie Bus on Bacon Cake Day, and enduring obnoxious company for go-kart racing access. Collaborative problem-solving defines their efforts during camping trips disrupted by Zombie Hunter Joe and model drone crashes interfering with dark rituals.

His personality emerges through varied interactions: determination surfaces when he outperforms Samurai Zombie in an online game, provoking her real-life challenge. Resourcefulness is evident as he and Zo Zo leverage Zombie Rich Girl's VIP status for festival entry. Family connections are noted through an incident involving his great-great-great grandmother's vase and a mission to mail his grandmother's birthday card despite postal opposition.

A physical discrepancy exists between portrayals: his eyes appear blue in the cartoon animation but yellow within the Roblox game adaptation.