Masaki Jōgasaki serves as an eighth-year super senior and president of the Kyoto University movie circle. He projects a charismatic, handsome image publicly, masking private lecherous inclinations, including owning a life-sized love doll named Kaori whom he treats with doting care. His antagonistic dynamic with the protagonist involves manipulating circumstances to thwart the protagonist's goals, frequently aided by Ozu despite Ozu's simultaneous alliance with the protagonist. This duality defines his complex role across multiple timelines.

A longstanding rivalry, termed the "proxy-proxy war," exists between Jōgasaki and Seitarō Higuchi, rooted in their past as classmates alongside Hanuki and the ramen stall owner. This conflict fuels elaborate pranks and power struggles throughout the series. Within the film circle timeline, Jōgasaki's darker traits surface: he auditions female members based on physical attributes, meticulously documents their breast sizes in illustrated records, and exhibits germophobia by discarding gifts over contamination fears. These actions prompt the protagonist and Ozu to plot his exposure through a manipulated documentary.

Alternate timelines reveal contrasting facets: Jōgasaki mentors the protagonist for an athletic competition, employs him to care for Kaori, and joins comical escapades like Higuchi's pranks, showcasing his playful, good-humored, and creatively engaged sides. His character design shifts to reflect the narrative perspective. When viewed through the protagonist's biased lens—especially in contexts depicting him as a "dictator"—visuals render him grotesquely or in militaristic parodies. As the protagonist gains multi-faceted awareness, Jōgasaki's portrayal normalizes, emphasizing his nuanced humanity. In the sequel *The Tatami Time Machine Blues*, Jōgasaki continues his rivalry with Higuchi and involvement in collegiate antics.