Kouichi Toochika is a Japanese voice actor born on October 20, 1971, in Osaka Prefecture and raised in Yamaguchi Prefecture. He is affiliated with the Tokyo Actor's Consumer's Cooperative Society (Haikyo). Toochika graduated from the Katsuta Voice Actor Academy as part of its 10th class and later completed the Haikyo Voice Actors Studio's 5th term. He has been active in the industry since 1992.

Toochika is known for his versatile vocal range, described as a high baritone, and is fluent in both Kansai and Yamaguchi dialects. His career is marked by a wide variety of roles across anime, video games, tokusatsu, and dubbing.

In anime, he is widely recognized for his long-running role as Neji Hyuga in the Naruto series, including Naruto, Naruto Shippūden, and related film adaptations. Another significant and recurring role is that of Hawkmon in the Digimon franchise, appearing in Digimon Adventure 02, several films including Digimon Adventure: Last Evolution Kizuna and Digimon Adventure 02 The Beginning, and OVAs. He also voiced multiple characters in the Kinnikuman Nisei (Ultimate Muscle) series, specifically Check Mate and Ilioukhine.

His other notable anime roles include Hazel Grouse in Saiyuki Reload -ZEROIN-, Peath Glinhouse in Back Arrow, Toyohiro Kanedaichi in JoJo's Bizarre Adventure: Diamond Is Unbreakable, Yu Himura in the ef: A Tale of Memories series, Griffin Minos in Saint Seiya: The Hades Chapter, En Daidouji in Brave Command Dagwon, and Ryunosuke Kurumi in HeartCatch Pretty Cure!. He also voiced characters in long-running series such as One Piece, Bleach, and Fairy Tail.

Beyond anime, Toochika has a significant presence in tokusatsu (live-action special effects) series, providing voices for characters in Super Sentai and Metal Hero shows. Notable credits include B-Fighter Kabuto, B-Robo Kabutack, and the voice of Secret Lantern Daigoyou in Samurai Sentai Shinkenger and its subsequent film appearances. He has also lent his voice to numerous video games, often reprising his anime roles, and has performed lead roles in games like Dual Blade and Chōkō Senki Kikaioh.

His work also extends to narration for television programs and commercials, as well as voice-over work for foreign film dubs. A recognized achievement includes his role in the film Kazu & Yasu Hero Tanjō. Outside of his performance career, Toochika is known for his passion for Japanese history, particularly the Sengoku period and castle ruins, a hobby he shares through radio programs and by serving as a lecturer for castle tours.