# 2026年10月21日 山本耕史 - Show: 大竹メインディッシュ - 大竹まことゴールデンラジオ！ - Published: 2026-10-21 - Canonical: https://podc.club/en/episode/254179829_df173b4b9f3e.html - Audio: https://traffic.megaphone.fm/NCB9914038494.mp3 - Source: Edited from a machine transcript of the first 30 minutes of the episode. Not an official summary. Actor Yamamoto Koji (山本耕史) appeared on Otake Main Dish ahead of a concert marking his 50th anniversary in entertainment, tracing a career that began when he was a baby model at age zero. He described his awakening through the Broadway musical Rent, how playwright-director Mitani Koki (三谷幸喜) spotted something in him during a rehearsal and cast him as Hijikata Toshizo in the 2004 NHK taiga drama Shinsengumi!, and what audiences can expect from an anniversary concert featuring special guest Yamaguchi Tomohiro (山口智充) — thirty minutes packed with five decades of stories. ## What this episode answers ### Why was Yamamoto Koji working in entertainment from age zero? Both his parents were singers and his older brother was already working in entertainment, so his career had begun before he was old enough to feel any resistance to it. ### What did he mean when he said he used to deliberately perform badly at auditions as a child? He wanted to get back to playing with friends, so he would slack off during auditions — yet his unfocused, eager-to-leave demeanor was read as 'childlike authenticity,' and he kept getting cast anyway. ### What projects or events marked the turning points in his career? The Broadway musical Rent, which he performed in at ages 21 and 22, was the first turning point; the second was a stage production with Mitani Koki that led directly to the role of Hijikata Toshizo in the 2004 taiga drama Shinsengumi!. ### Why did Mitani Koki recommend Yamamoto for the role of Hijikata Toshizo in Shinsengumi!? Mitani witnessed Yamamoto firmly speak up during rehearsals about a song key that didn't suit him, and concluded that someone who looked gentle but had real inner strength was a perfect match for Hijikata. ### What can audiences expect at the 50th anniversary concert? The concert is built around songs from past productions, including 'Seasons of Love' from Rent, with no scripted dialogue or acting; special guest Yamaguchi Tomohiro will join him along with an improv songwriting segment. ## Article ## A Career That Started Before Memory — Age Zero Yamamoto Koji's career goes back to an age he has no memory of: zero. Both his parents were singers, and his older brother was already working in entertainment, so, as he put it, his career had started before he could feel any resistance to it. His earliest concrete memory comes from around age two — lying in a bed while a camera was pointed down at him from above and he was told to close his eyes and pretend to sleep. When he later described the scene to his mother, she was stunned: "You remember that far back?" As an elementary-school student he appeared in Les Misérables (レ・ミゼラブル) at the Imperial Theatre (帝国劇場), a venue that seats 2,000. Standing on stage surrounded by adults, what stayed with him wasn't a connection with the audience but the sheer stimulus of an environment no ordinary schoolchild ever encounters. ## Child-Actor Days — Trying to Fail on Purpose Auditions, Yamamoto laughs, were "a place he wanted to escape from as fast as possible." He wanted to go play with his friends, so he would deliberately hold back. While other child actors worked hard to impress, he would drift along looking vague and ready to leave — and that unfocused quality apparently read as childlike authenticity. He kept getting cast anyway. "Saying I didn't try my hardest is a strange way to put it," he admitted with a rueful smile. Throughout his career Yamamoto has remained independent, without signing to a large agency — uncommon in the Japanese entertainment industry. While peers were landing TV drama roles, he was shooting period dramas in Kyoto and appearing on stage, carving out what he describes as a "niche" path. That record eventually made him the rare young actor who could handle both period pieces and theatrical work, and it attracted the right attention at the right time. ## First Turning Point: Rent at Age 21 The moment Yamamoto names as his first turning point is the Broadway musical Rent (レント), which he performed in at ages 21 and 22. "That was when I could see the outline — maybe this is the kind of performer I am, maybe this is the path I'm on," he said. But clarity cut both ways: once he knew what he was after, he became increasingly unwilling to take jobs that didn't fit. A stretch of "I don't want to do this — or that either" followed. The sharper the vision, the harder it was to settle. ## Second Turning Point: One Remark by Mitani Koki and Shinsengumi! The second turning point came through a stage production with Mitani Koki. During rehearsals, Yamamoto noticed that the key of a song didn't suit him and went directly to the person in charge of the music: "Whose solo is this? If the key is set for the chorus, I'd like it changed, because this is my solo." Mitani was watching from the side and later said he had assumed Yamamoto was a gentle, mild-mannered person — and then realized he wasn't. That observation led Mitani to recommend Yamamoto for the role of Hijikata Toshizo in the 2004 NHK taiga drama Shinsengumi!. Mitani's reasoning: Yamamoto had a soft, un-period-drama look on the outside, while Hijikata — known as the Demon Vice-Commander — was all iron within. That contrast, Mitani said, fit Yamamoto perfectly. Looking back, Yamamoto reflected: "There are people watching, even when you don't know it." He also admitted that around this time he was struggling with the gap between the "gentle and quiet" image others projected onto him and who he actually was, wondering whether he ought to simply perform that image — while never quite losing the sense that it wasn't really him. ## The 50th Anniversary Concert and What Comes Next The anniversary concert takes place on October 24 in Osaka and October 31 in Tokyo at LINE CUBE SHIBUYA (LINEキューブ渋谷). There will be no scripted dialogue or acting; the program is built around songs from past productions, including "Seasons of Love" from Rent. Special guest Yamaguchi Tomohiro, his co-star from Shinsengumi!, will appear, and a segment in which the two create songs on the spot from audience-given prompts — a feature from a previous program together — is planned. Because there's no telling how long that segment will run, Yamamoto laughed that "the length of the concert will change." He also noted that he has played guitar since childhood, when Noguchi Goro (野口五郎) gave him his first instrument. On his future, Yamamoto said he wants to set his own pace rather than run himself ragged: "I have a family now, so my immediate goal is staying healthy and giving everything to the work that comes my way." Rather than chasing specific dream roles — no mention of Broadway ambitions — he is prioritizing a sustainable balance. He keeps up five to six training sessions a week, an ethic shaped largely by his father, who practiced judo. ## Takeaways - Yamamoto's career started at age zero through family connections in entertainment, long before he had any say in the matter. - Two moments defined his career: his self-discovery performing Rent at 21-22, and Mitani Koki recognizing his hidden toughness during rehearsals and casting him as Hijikata Toshizo in the 2004 taiga drama Shinsengumi!. - His 50th-anniversary concert, featuring guest Yamaguchi Tomohiro, centers on musical performances with no acting, and he plans to prioritize a sustainable, family-first pace going forward.