Masaru Hamaguchi (Japanese: 濱口 優, Hepburn: Hamaguchi Masaru, born January 29, 1972) is a Japanese comedian and actor from Konohana-ku, Osaka. He is the tsukkomi of the manzai duo, Yoiko, with his partner Shinya Arino.

Hamaguchi and Arino were classmates that graduated high school and formed a manzai duo in 1990.^[1] The duo would make their first major televised appearance on Mecha-Mecha Iketeru! in 1996.^[2]

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• Mecha-Mecha Iketeru! (1996–2018)
• Ikinaru! Ougon Densetsu.

Hamaguchi was born into a family that owns a coffee shop called "Hamayū" (はまゆう) in Konohana-ku, Osaka, named after the poisonous spider lily from his grandfather's love of lily flowers on the beach.^[3]

In 2013, Hamaguchi began dating the gravure idol Akina Minami. They got married on May 25, 2018,^[4][5] initially giving birth to a stillborn^[6][7] before his wife gave birth to a healthy baby, their son in 2022.^[8]

• Masaru Hamaguchi's channel on YouTube
• Masaru Hamaguchi and Akina Minami's channel on YouTube
• Masaru Hamaguchi on Instagram
• Masaru Hamaguchi on Twitter