TV-Series
Description
Seitaro Higuchi is an eighth-year university student living in the protagonist's dormitory. He earned the nickname "Master Higuchi" or "the Master" due to his perceived wisdom and detached air. His distinctive appearance features an eggplant-shaped face, contributing to an ambiguous, potentially inhuman aura; whether he is an eccentric senior or a supernatural entity remains unresolved.

He consistently wears traditional Japanese clothing like a yukata or kimono, emphasizing his eccentric personality and dedication to nonconformity. This attire subtly reinforces his existence outside conventional university life. His daily habits include smoking weed and maintaining a free-spirited romantic relationship with a woman who has already graduated, reflecting his rejection of societal norms.

Higuchi recurs across the protagonist's parallel timelines, often acting as a mentor offering philosophical insights. He demonstrates nuanced understanding of human relationships, capitalism's impact on college life, and self-acceptance. He once advised the protagonist on embracing personal flaws after noticing his emotional turmoil, though the protagonist only partially understood. His depth is further illustrated when he emotionally finished reading "20,000 Leagues Under the Sea."

A defining aspect of his background is his longstanding rivalry with fellow eighth-year student Masaki Jogasaki. This conflict, known as the "proxy-proxy war," stems from their shared history as former classmates and involves elaborate, indirect confrontations. Higuchi's past connections also include Hanuki, a dental hygienist, and the owner of a ramen stall, both part of his university cohort.

His mischievous tendency emerges in morally ambiguous schemes, like attempting to steal Jogasaki's sex doll, Kaori. These plans are frequently thwarted by Akashi, who criticizes his actions across timelines. Higuchi also evades university authorities for years over an extremely overdue library book, showcasing his disregard for institutional rules. In one timeline, he humorously introduced himself with the overly long alias "Kamotaketsunuminokami," emphasizing his enigmatic and playful nature.

In the sequel *The Tatami Time Machine Blues*, Higuchi appears again, maintaining his established traits and involvement in the characters' lives.