Kōji Seto

Kōji Seto (瀬戸 康史) is a Japanese actor and singer associated with D-Boys, an acting troupe produced by Watanabe Entertainment. His major works include lead roles as Wataru Kurenai in Kamen Rider Kiva; and supporting roles as Satoru Okura in Atashinchi no Danshi, Ariake Yamato in Otomen, and Eiji Kikumaru in Tenimyu. He starred as Mori Ranmaru in the drama, Gō: Hime-tachi no Sengoku.

In 2010, he was named one of the most promising actors and actresses, placing 7th in a poll conducted by Oricon. Through his role with Kamen Rider Kiva, he was also the lead vocalist of the J-Rock band Tetra-Fang. Seto is a member of D-Boys.

Life and career
Born in 1988 in Kyushu, Kōji Seto grew up as the oldest child with two younger sisters. His childhood dream of becoming a vet changed suddenly with the end of his Junior High School time, when he watched with 15 years the TV series Orange Days. The praised drama and performance by Satoshi Tsumabuki inspired his wish to become an actor. After discussing his plans with his parents, they decided to support their son and enrolled him to a local acting school.

After one year in training, he was cast in 2005 as Makoto Kanno in the television series Rocket Boys. After the filming ended, he was accepted final round of Watanabe Entertainment's 2nd official D-Boys audition. With his interpretation of Masaharu Fukuyama's song "Himawari" won Seto the Grand Prix 2nd Winner Award on July 31, 2005. He debuted as a Junior member just shortly afterwards in December at the 3rd D-Live Event - an entertainment show featuring only D-Boys members.

In spring 2006, at the age of 17, he finally moved after constant commuting from his rural and idyllic hometown in Fukuoka to live by himself in Tokyo. Seto starred together with all his fellow D-Boys members in their first own TV production "DD-Boys" and won, at the same time, the audition for Eiji Kikumaru in Musical: The Prince of Tennis and played him until September 9, 2007. He and his stage partner Yukihiro Takiguchi were honored with a Best Actors Album and praised by the creator of the original work Takeshi Konomi as perfect cast.

Seto's official D-Boys logo is a chameleon, in reference to his versatility. In late 2006 he was chosen as Thursday's-face of Oha Suta, a children's TV show airing live every morning on TV Tokyo. He co-hosted the show constantly from then, once a week together with Kōichi Yamadera, until his graduation on April 28, 2008. He starred in his first leading part in spring 2007 as Kyoichi Segawa in Happy Boys. Right after this series, he played Tibe-kun in the live-action film adaptation of ''[[Tonari no Yaoi-chan.

The part of Izamu Hayama in the feature film Tenshi ga Kureta Mono was his first cinema production in autumn 2007. He then co-starred in winter 2007 with Aya Ueto and Yo Oizumi in his first Golden Time TV series Abarenbo Mama as a kindergarten teacher. From January 2008 to 2009 he starred as one of Toei's Tokusatsu Heros, the young violinist and half-vampire Wataru Kurenai, the protagonist in Kamen Rider Kiva. About the same time, was Seto chosen among 1000 competitors in an audition for the leading part as the rebel Hiroki "Hiro" Sakurai, in the TV series adaption of Koizora (after the bestseller book by Mika), making him the leading actor for two TV series filmed and broadcast at the same time. Both works earned him a nomination for the renowned Elan d'Or award as Best Newcomer of the Year 2009.

In early 2009, Seto started filming for the latest Ju-On movie Ju-On - Black Girl. He reprised his role as Wataru Kurenai for the first and last episode of Kamen Rider Decade, as well as in Decade: Last Story, the last part of the storyline, as a guest star. Afterwards, he starred as the hotheaded genius-magician Satoru Okura in the Fuji TV drama Atashinchi no Danshi as one of Maki Horikita's six sons, followed by his part as the cheerful, but delusional junior Ariake Yamato in the drama adaption of the Hit-Manga Otomen in Summer. At the end of October, he finished filming with Yusuke Yamamoto for their roles as brothers (having previously starred as brothers in Atashinchi no Danshi) in the award-winning TV movie Rinne no Ame, in which Seto portrayed the mentally disabled, autistic Shuhei Mikami.

In early 2010, he played Shunta Matsumoto, a young medical student in the BeeTV drama Gift, a part that was written for him, as an alternative version of himself. In the spring TBS TV series Tumbling, Seto is starring as Yuta Takenaka, captain to the boy's rhythmic gymnastics team at Karasumori High, alongside Yusuke Yamamoto again. For the 10th anniversary commemoration of Watanabe Entertainment, he was selected with fellow D-Boys members Shunji Igarashi, Yuichi Nakamura, and Hirofumi Araki to represent all members of the group in a special unit with a new fifth member determined through the 2010 D-Boys Audition. Recently, he's been filming and played as Mori Ranmaru for the latest Taiga drama Gō for 2011.

Personal life
In 7 August 2020, Seto married his costar in TV dramas Hope: Kitai Zero no Shinnyu Shain and Perfect World, Mizuki Yamamoto.

On 29 January 2022, his wife, Yamamoto, made the announcement that she was expecting their first child. The couple's first child was born on 16 May 2023.

Television
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 * rowspan="2"| 2005
 * Rocket Boys
 * Makoto Kanno (main cast)
 * TV series filmed 2005, broadcast 2006 (TV Tokyo)
 * 3rd D-Live (D-Boys Live Entertainment Show)
 * Himself
 * Stage debut
 * rowspan="6"| 2006
 * Hit Parade
 * The Tigers member (Guest Star)
 * 2-part TV movie
 * DD-Boys
 * Himself
 * TV documentary series (TV Asahi)
 * Tenimyu - Advancement Match Rokkaku feat. Hyotei Gakuen
 * Eiji Kikumaru (main cast)
 * Stage musical
 * Yume no Kobako ni Ribbon wo Kakete ~Revised Edition~ (Dream in a Ribbon Box)
 * Young Thief (main cast)
 * Stage Play (re-run)
 * OhaSuta
 * Seto-kun (co-presenter)
 * Children morning show (TV Tokyo)
 * Tenimyu - Absolute King Rikkai feat. Rokkaku ~ First Service
 * Eiji Kikumaru (main cast)
 * Stage musical
 * rowspan="11"| 2007
 * Happy Boys
 * Kyoichi Segawa (Lead)
 * TV series (TV Tokyo)
 * Tonari no Yaoi-chan
 * Chibe-kun (Lead)
 * Movie
 * Tenimyu - Dream Live 4th
 * Eiji Kikumaru (main cast)
 * Stage musical
 * Out of Order
 * Guest star appearance
 * Live entertainment stage show
 * Tenimyu - Dream Live 4th ~Extra~
 * Eiji Kikumaru (main cast)
 * Stage musical
 * D-Boys Stage Volume 1 ~Kanbai Gore~
 * Genki-kun/Souji Okita (Lead)
 * Stage play
 * Thrill Night - United States of Ikemen
 * Himself
 * Celebrity entertainment show (Fuji TV)
 * Tenshi ga Kureta Mono
 * Izamu Hayama (main cast)
 * Cinema debut, motion picture
 * Tenimyu - Absolute King Rikkai feat. Rokkaku ~ Second Service
 * Eiji Kikumaru (main cast)
 * Stage musical
 * Abarenbo Mama
 * Naoya Abe (main cast)
 * Prime-time TV series (Fuji TV)
 * Nekketsu! Heisei Kyouiku Gakuin
 * Guest Star Candidate
 * Celebrity quiz show (Fuji TV)
 * rowspan="8"| 2008
 * 45th secret New Years Performance Tournament
 * Ikemen Jumper
 * New Years celebrity entertainment show (Fuji TV)
 * Bandai's Kamen Rider Kiva DX Belt CM
 * Wataru Kurenai
 * TV commercial
 * Kamen Rider Den-O & Kiva - Climax Deka
 * Wataru Kurenai / Kiva (Guest Star)
 * Motion picture
 * Shakariki
 * Cameo (himself)
 * Motion picture
 * D-Boys Stage Volume 2: The Last Game
 * Kaoru Betto (main cast)
 * Stage play
 * Guest Star Candidate
 * Celebrity quiz show (Fuji TV)
 * rowspan="8"| 2008
 * 45th secret New Years Performance Tournament
 * Ikemen Jumper
 * New Years celebrity entertainment show (Fuji TV)
 * Bandai's Kamen Rider Kiva DX Belt CM
 * Wataru Kurenai
 * TV commercial
 * Kamen Rider Den-O & Kiva - Climax Deka
 * Wataru Kurenai / Kiva (Guest Star)
 * Motion picture
 * Shakariki
 * Cameo (himself)
 * Motion picture
 * D-Boys Stage Volume 2: The Last Game
 * Kaoru Betto (main cast)
 * Stage play
 * Motion picture
 * D-Boys Stage Volume 2: The Last Game
 * Kaoru Betto (main cast)
 * Stage play
 * Stage play


 * Koizora
 * Hiroki "Hiro" Sakurai (Lead)
 * TV series (TBS)
 * rowspan="8"| 2009
 * Kamen Rider Decade
 * Wataru Kurenai (Guest Star)
 * Tokusatsu TV series (TV Asahi)
 * Nakai's Super Drama Spring Festival
 * Participant
 * TV show
 * Atashinchi no Danshi
 * Satoru Okura (main cast)
 * TV series (Fuji TV)
 * Ju-On - Black Girl
 * Tetsuya (Lead)
 * Horror motion picture
 * Nakai's Super Drama Sommer Festival
 * Participant
 * TV show
 * Otomen
 * Ariake Yamato (main cast)
 * TV series (Fuji TV)
 * D-Boys Stage Volume 3: Karasu 10
 * Ryuu (Lead)
 * Stage play
 * Kamen Rider × Kamen Rider W & Decade: Movie War 2010
 * Wataru Kurenai / Kiva (Guest Star)
 * Motion picture
 * rowspan="4"| 2010
 * Rinne no Ame
 * Shuhei Mikami (Lead)
 * TV movie (Fuji TV)
 * Gift: Tonight, we will deliver a happy time
 * Shunta Matsumoto (main cast)
 * Mobile series (BeeTV)
 * Tumbling
 * Yuta Takenaka (main cast)
 * TV series (TBS)
 * D-Boys Stage 2010 Trial 2: The Last Game
 * Suishu Tobita (Lead)
 * Stage play (Pre-Production)
 * rowspan="3"| 2011
 * Runway Beat
 * Biito "Beat" Mizorogi (main cast)
 * Motion picture
 * Moshidora
 * Keiichiro Asano (main cast)
 * Motion picture
 * rowspan="2"| 2012
 * Teen Court: 10-dai Saiban
 * Saburo Takada
 * TV series (NTV)
 * Sadako 3D
 * Takanori Ando
 * Movie
 * 2013
 * Saito-San 2
 * Teacher
 * TV series (NTV)
 * 2014
 * My Hawaiian Discovery
 * Motion picture
 * rowspan="3" |2015
 * Age Harassment
 * Ikawa Yu
 * TV series, TV Asahi
 * Asa ga Kita
 * Izumi Narusawa
 * TV series (NHK), Asadora
 * Mercury Fur
 * Darren
 * Stage play
 * rowspan="2" |2016
 * Watashi Kekkon Dekinain ja nakute, Shinain Desu (It's Not That I Can't Marry But I Don't Want To)
 * Ryotaro Hashimoto
 * TV series (TBS)
 * 2014
 * My Hawaiian Discovery
 * Motion picture
 * rowspan="3" |2015
 * Age Harassment
 * Ikawa Yu
 * TV series, TV Asahi
 * Asa ga Kita
 * Izumi Narusawa
 * TV series (NHK), Asadora
 * Mercury Fur
 * Darren
 * Stage play
 * rowspan="2" |2016
 * Watashi Kekkon Dekinain ja nakute, Shinain Desu (It's Not That I Can't Marry But I Don't Want To)
 * Ryotaro Hashimoto
 * TV series (TBS)
 * Stage play
 * rowspan="2" |2016
 * Watashi Kekkon Dekinain ja nakute, Shinain Desu (It's Not That I Can't Marry But I Don't Want To)
 * Ryotaro Hashimoto
 * TV series (TBS)
 * TV series (TBS)

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 * rowspan="3" |2017
 * Bakumatsu Gourmet Bushi Meshi!
 * Sakai Banshiro
 * TV series (NHK)
 * Toga no Hito
 * Sakito Nakamoto
 * Narratage
 * Manpuku
 * Shigeru Kanbe
 * TV series (NHK), Asadora
 * rowspan="3" |2019
 * rowspan="1" |2020
 * Stigmatized Properties
 * Manpuku
 * Shigeru Kanbe
 * TV series (NHK), Asadora
 * rowspan="3" |2019
 * rowspan="1" |2020
 * Stigmatized Properties
 * Stigmatized Properties