Kensuke Shibagaki, a 34-year-old comedian, forms half of the manzai duo Homosapiens alongside partner Atsuya Baba. As the "boke" (funny man), Shibagaki delivers humorous lines and setups, countered by Baba's "tsukkomi" (straight man) reactions. Shibagaki possesses strong ambitions for comedic fame and success but contends with ongoing creative clashes with Baba, whom he considers less experienced. Their strained partnership faces professional setbacks, notably repeated failures to advance past the qualifying rounds of the "N-1 Grand Prix" competition.

Financially unstable, Shibagaki supplements his income with part-time work at a cabaret club due to the duo's lack of sustainable earnings from comedy. During a low point, high school student and Homosapiens fan Satoshi Nagashima approaches Shibagaki with an offer to become his new comedy partner. Nagashima predicts the duo's dissolution due to their stagnation and promises Shibagaki greater success. This proposal creates a moral dilemma for Shibagaki as he contemplates abandoning Baba, though he hesitates fearing public criticism for partnering with a teenager.

A key revelation in the series finale clarifies that Shibagaki's depiction as a wild boar results from protagonist Hiroshi Odokawa's visual agnosia, a psychological condition causing Odokawa to perceive humans as anthropomorphic animals. Shibagaki is human; his animal appearance exists solely through Odokawa's subjective perception. The film *In the Woods* reconstructs the series' events, including Shibagaki's role within the interconnected narratives, without introducing new character developments or backstory beyond the original storyline. His background remains centered on his comedic career, financial pressures, and ethical challenges within the entertainment industry.