Tarou Jiroumaru, a 31-year-old novelist, frequently stays at the Kissuisō hot spring inn, occupying the Wave Room while writing manuscripts. He specializes in erotic stories, using the inn's staff as character references without their initial awareness, though owner Sui Shijima learns of this early.

Financially strained, Tarou accrues unpaid lodging fees, leading him to take part-time labor at Kissuisō to settle debts. Before novel writing, he worked as a manga artist. One short-lived cooking-themed manga series, spanning few volumes, inadvertently inspired both Minko Tsurugi and Tōru Miyagishi to become chefs.

Tarou habitually fabricates or exaggerates stories to embellish his life, eroding staff trust and inviting reprimands. When Ohana Matsumae discovers his missing erotic manuscript drafts—revealing staff-inspired content—he panics, briefly confines her, and flees by stealing an inn vehicle. Staff pursue him, culminating in Tarou leaping into the sea in despair. Nako Oshimizu rescues him; afterward, he laments his perceived lack of talent. Ohana intervenes, slapping him and acknowledging his unconventional writing provided unexpected self-reflection. This motivates Tarou to persist.

As a Kissuisō laborer, he assists with miscellaneous tasks, integrating into daily operations while continuing to write. His presence adds comedic and occasionally disruptive dynamism through gossip-driven interactions and ongoing efforts to balance creativity with responsibilities.