Sarutobi Satori serves as Sarutobi Hideyoshi's younger sister, appearing solely in the original manga and OVA series. Her first interaction with Nagasumi Michishio occurs during a cinema fire where he saves her. This rescue prompts her to affectionately dub him "Nagasumi Willis," a recurring nickname inspired by the fictional action hero Bunta Willis—a composite parody of Bruce Willis and Bunta Sugawara—reflecting her admiration for cinematic heroes.

Satori balances politeness with boldness, presenting as well-mannered yet unrestrained. She shows minimal deference to elders and occasionally acts impulsively. Despite her youth, she displays cleverness, skillfully adopting an innocent child persona to manipulate adults for her goals.

Her passion for action films centers on the Bunta Willis franchise, a shared interest with Sun Seto that sparks an immediate friendship. This bond highlights Satori’s tendency to connect through common enthusiasms.

Satori reunites unexpectedly with her brother Saru during the cinema incident, having never met him prior. The encounter underscores her energetic, sometimes heedless nature. While sharing Saru’s assertiveness and wit, she lacks his flirtatiousness and instead exhibits greater courage and moral conviction.

Her story involvement is confined to the original manga and OVAs, specifically the "The Man Who Doesn't Die" segment of the first OVA—a narrative directly referencing the Die Hard films. Her role intertwines with the film-viewing scenario and subsequent theater rescue.