Toshiyuki Hosokawa was a Japanese actor whose primary career was in live-action stage, film, and television, but he is also remembered for a notable foray into anime voice acting. Born in Fukuoka, Japan on December 15, 1940, Hosokawa began his acting career after leaving Gakushuin University when he joined the respected Bungakuza theatrical troupe in 1964. He became a prominent figure in Japanese entertainment, earning recognition for his work across multiple performance mediums. In 1970, he landed a starring role in the Yoshishige Yoshida-directed film Eros Plus Massacre, which brought him significant prominence. That same year, he began a long-running engagement with the musical Show Girl, co-starring with actress Nana Kinomi in a production that would last for 15 years.

Hosokawa's venture into voice acting was closely tied to the classic boxing anime franchise Ashita no Joe (known as Tomorrow's Joe). He provided the voice for Toru Rikiishi, the most formidable rival of protagonist Joe Yabuki, in two animated feature films. His first performance as Rikiishi was in the 1980 film Ashita no Joe, and he reprised the role the following year in its sequel, Tomorrow's Joe 2, which was released in 1981. The character of Rikiishi is a complex and tragic figure, a skilled boxer whose intense rivalry with Joe drives much of the story's emotional weight. Hosokawa delivered a memorable performance for this iconic role, even though his vocal work was largely limited to these two productions.

Throughout his career, Hosokawa built an extensive filmography in live-action cinema and television. He appeared in numerous films across several decades, including Zatoichi Meets Yojimbo in 1970, Female Prisoner Scorpion: #701's Grudge Song in 1973, The Makioka Sisters in 1983, and Welcome Back, Mr. McDonald in 1997. His television work was equally prolific, with roles in historical dramas such as Sekigahara in 1981, Hachidai Shōgun Yoshimune in 1995, and Aoi Tokugawa Sandai in 2000. Hosokawa also served as a professor at the Osaka University of Arts, a position he held from 2004 onward. Toshiyuki Hosokawa passed away on January 14, 2011, at a hospital in Tokyo at the age of 70, following an accidental fall at his home that resulted in a subdural hematoma.