Seki Toshihiko was born on June 11th, 1962 in Tochigi. His blood type is A. He is 167 cm tall and weighs 61 kg. His three sizes are 94-75-95. His shoe size is 24.5 cm. He works for 81 Produce.
Toshihiko has done the following roles in anime.
| Ai no Kusabi | Riki |
| Akai Hayate | Nagase Jun |
| Angel Cop | Tachihara |
| Antique Heart (Gakuen Benriya Series) | Honda Takahiro |
| Armor Hunter Mellowlink | Sepres |
| B.B | Sorry |
| Babel II | Nicola |
| Bastard! | Karu Su |
| Bio Hunter | Komada |
| Black Jack | Umetani Tokio |
| B'T X {Neo} | Quatro |
| Call Me Tonight | Hayata |
| CLAMP Gakuen Tanteidan {episode 1} | husband |
| Cyber Formula | Breed Kaga |
| Demon Hunter | Tetsuo |
| Detonator Orgun | Nock |
| Devastator | Yatabe Ryo |
| Dodge Danpei | Nikaidou |
| Dragon Century | Carmine |
| Dragoon | Lane |
| Evangelion | Asuka's father |
| F | Gunma |
| Flag! | Nobel |
| Fuuma no Kojiro | Reira |
| Genesis Surviver Gaiarth | General |
| Gensou Maden Saiyuuki | Genjou Sanjou |
| Goddamn | Hans |
| Granzort | Grunwald |
| Gundam Wing | Duo Maxwell |
| Hakkenden | Inuzuka Shino |
| Hakugei Densetsu | Dew |
| Hameln no Violin Hiki (movie) | Raiel |
| Handsome na Kanojo | Kumagai Ichiyo |
| Haunted Junction | Haruto's father |
| Hikaruon | Hikaru |
| Idol Tenshi Youkoso Yoko | Hayami Ryou |
| Izumo | Izumo |
| Juubei Ninpouchou [Ninja Scroll] | Yurimaru |
| Karura Mau | Shinguuji |
| Kaze wo nuke! | Ryuuichi |
| Kindaichi Shounen no Jikenbo | Naoto |
| Koko ha Greenwood | Tezuka Shinobu |
| Kruel 1999 | Juurou |
| Kujaku-Oh | Kujaku |
| Legend of Crystania | Nursel |
| Musekinin Kanchou Tylor | Dom |
| Natsuki Crisis | Himuro Kyoutarou |
| Nintama Rantarou | Doi-sensei |
| Odaijini | Yamashita |
| Oi! Ryouma | Sakamoto Ryuuma |
| Outlaw Star | Fred |
| Pet Shop of Horror | Count D |
| Please Save My Earth | Yakushimaru Mikuro |
| Pollyanna | young John |
| Princess Army | Hashiba Yuuya |
| Ranma 1/2 | Mousse |
| Ryokunohara Labyrinth | Imanishi Hiroki |
| Ryuuki Denshou | Rain |
| Saint Seiya | Fenril |
| Samurai | Chimatsuri |
| Shihaisha no Tasogare | Shijo Tsunami |
| Shurato | Shura-Oh Shurato (Hidaka Shurato) |
| Starcat Full House | Seitarou |
| The Weathering Continent | Tieh |
| To-Y | Shouji |
| Tokumu Sentai Shinesman | Seki Shujin |
| Touch [debut] | Fujimoto |
| Touch{3} | Nakajima |
| Transfer Student of Fire | Takisawa Noboru |
| Trigun | Legato Bluesummers |
| Umi ga Kikoeru | Matsuno Yutaka |
| Umi no Yami, Tsuki no Kage | Touma Katsuyuki |
| Wedding Peach {episode 11} | Tanma |
| Wild 7 | Hiba |
| X | Shougo |
| Yawara! | Matsuda Kousaku |
| Youseiki Suikoden | Suga Takateru |
| Yuugen Kaisha | Mukyou |
| Yuukan Club | Shouchikubai Miroku |
| Zeorymer | Masato |
| Zillion | JJ |
