Yūichi Nagashima is a prolific Japanese voice actor, currently known by the stage name Chō (stylized as チョー). He was born Shigeru Nagashima on December 15, 1957 in Saitama, Japan. He adopted the name Yūichi Nagashima early in his career before changing his stage name to Chō in 2006, in honor of a character he had portrayed on the children's television program Tanken Boku no Machi. He is a graduate of Nishogakusha University and a member of the Tokyo Actor's Consumer's Cooperative Society (Haikyō).

Nagashima is best known for his extensive work in anime, frequently voicing older male characters, villains, and eccentric figures. His most globally recognized role is Brook, the skeleton musician of the Straw Hat Pirates in the long-running series One Piece. He has voiced this character across many iterations of the franchise, including the main series, several television specials such as One Piece 3D2Y: Overcoming Ace's Death!, One Piece Special – Adventure of Nebulandia, and One Piece Episode of Merry: Mō Hitori no Nakama no Monogatari, as well as feature films like One Piece: Glorious Island and One Piece Episode of Luffy: Hand Island no Bōken.

Another signature role is Jaken, the loyal and often comedic vassal to the titular character in InuYasha. He reprised this role for the three InuYasha feature films: Affections Touching Across Time, Swords of an Honorable Ruler, and Fire on the Mystic Island. His other prominent anime roles include Hiroshi Uchiyamada, the beleaguered vice-principal in Great Teacher Onizuka (GTO), and the principal in both Hidamari Sketch and the surreal comedy Nichijou. He also portrayed Hiroshi Yushima in Digimon: Data Squad (known as Digimon Savers in Japan), Kawakubo in Steam Detectives, and Kyasharin in Sexy Commando Gaiden: Sugoi yo!! Masaru-san.

Nagashima has also had a significant presence in tokusatsu productions and dubbing for foreign media. In live-action Japanese television, he is known for the role of Hone no Shitari in Samurai Sentai Shinkenger. In the field of dubbing, he has provided the Japanese voice for a wide array of characters in Western films and television series, including Gollum in The Lord of the Rings film trilogy, the title character in the live-action Scooby-Doo film, Neelix in Star Trek: Voyager, and Seymour Simmons in the Transformers live-action film series. He has also voiced characters in animated properties such as Tarantulas in Beast Wars, Alpha Q in Transformers: Energon, Blitzwing in Transformers: Animated, and Elmer Fudd in Looney Tunes.

His voice acting work extends into video games, with roles including Professor Pickle in Sonic Unleashed, Hanks in Tales of Vesperia, Kazuo Yamashita in Kengan Ashura, the character Dragon's Dream in JoJo's Bizarre Adventure: Stone Ocean, and Ramon Salazar in the 2023 remake of Resident Evil 4. With a career spanning from the 1980s to the present day, Yūichi Nagashima, or Chō, remains a highly active and respected figure in Japanese animation and voice acting.