A Japanese of Korean descent, Ihara joined the Japan Action Enterprise, a theater troupe founded by Sonny Chiba , after leaving high school.Soon after, he began to act in numerous feature films and television dramas , including the 1996 NHK seriesFutarikko. In 2006, Ihara appeared as the Baron Takeichi Nishi in Clint Eastwood 's critically-acclaimed Academy Award -winning filmLetters from Iwo Jima, introducing him to an international audience.He has also authored a book,Kokorozashite Sōrō(志して候う^?), which was published in Japan by Amoeba Books.

Television dramas

• Hattori Hanzō: Kage no Gundanseries ( Fuji TV , 1980-)
  • Kage no Gundan IV
  • Kage no Gundam Bakumatsu-hen
• Takeda Shingen(1988 NHK Taiga drama ; portraying Oda Nobuyuki )
• Oishii no ga suki( TBS , 1989)
• Kyō, Futari(1990 NHK morning drama )
• Yonimo Kimyōna Monogatari(1991, Fuji TV )
• Futarikko(1996 NHK morning drama)
• Only You ~Aisarete~(1996, Nippon TV)
• Ichigen no Koto(2000, NHK)
• Star no Koi(2001, Fuji TV)
• Kowloon de Aimashō(2002, TV Asahi )
• Kochira Hon Ikegami Sho(2002, TBS)
• Mibu Gishi Den ~Shinsengumi de Ichiban Tsuyokatta Otoko~(2002; portraying Hijikata Toshizō )
• Koi wa Tattakai(2003, TV Asahi)
• Kochira Hon Ikegami Sho 2(2003, TBS])
• Chūshingura ~ Ketsudan no Toki(2003, TV Tokyo ; portraying Horibe Yasubei )
• Sky High 2(2004, TV Asahi)
• Shinsengumi!(2004 NHK Taiga drama; portraying Sasaki Tadasaburō )
• Last Christmas(2004, Fuji TV)
• Kochira Hon Ikegami Sho 4(2004, TBS)
• Magari Kado no Kanojo(2005, Fuji TV)
• Shiawase ni Naritai!(2005, TBS)
• Koi no Jikan(2005, TBS)
• Grave of the Fireflies(2005, Nippon TV)
• Umeko(2005, TBS)
• Kuroi Taiyō(2006, TV Asahi)
• Nyotei(2007, TV Asahi)
• Team Batista no Eiko(2008, Fuji TV)

Films

• Kotaro Makaritoru(1984)
• Bakayarō! Watashi Okkote Masu(1988, Kōwa International and Shochiku )
• Hong Kong Paradise(1990, Toho )
• Daida Kyōshi Akiba, Shinken Desu!(1991, Toei and Nippon TV )
• Jingi(1991, Toei )
• Shura no Teiou(1994)
• Yonshima Monogatari(1995, Ezaki Guriko)
• Gamera: Guardian of the Universe(1995, Daiei )
• Abunai Deka Returns(1996, Nippon TV , Toei )
• Gamera 3: Awakening of Irys(1999, Daiei)
• Minna no Ie(2001, Fuji TV , Toho )
• Hanochi(2004)
• Hinagon(2005)
• Letters from Iwo Jima(2006) - portraying Baron Takeichi Nishi
• Retribution(2006)
• Heat Island(2007)
• Ninja(2009)
• Thirteen Assassins(2010)

Anime

• Karasu(1995, Toei )

Theater

• We Love JAC(1986)
• Jōji ta JAC Kōen
• Mayonaka no Party(1991)
• Honkon Rhapsody(1993)
• Dā! Dā! Dā!(1993)
• Hikoma ga Yuku(2002)
• Blood Gets in Your Eyes(2003)
• Rōnin Gai(2004)
• Kātenkōru(2005)
• shuffle(2005)
• Letters from Iwo Jima(2006)

Other programs

• Kimama ni Toygyazā( Mainichi Broadcasting System , Kansai Local)
• Ōra no Izumi(December 13, 2006, TV Asahi )

Books

• Kokorozashite Sōrō(author)

1. "Tsuyoshi Ihara - Biography" .Internet Movie Database. . Retrieved 2007-08-16.
2. Peter Travers(2007-12-06)."Letters From Iwo Jima : Review : Rolling Stone" .Rolling Stone. . Retrieved 2007-08-16.
3. "Amazon.co.jp： 志して候う: 本: 伊原 剛志" .Amazon.co.jp. . Retrieved 2007-08-16.