[2] As an actor, he appeared in many television shows and movies, such as Blackmail Is My Life (1968), Proof of the Man (1977), Zatoichi (1989) and Deadly Outlaw: Rekka (2002).

[3] He is also recognized for 20 years of charity and volunteer work with the Japan International Cooperation Agency and flew around the world helping those in poor or war-torn conditions; visiting more than 30 countries including Afghanistan, Myanmar, Bosnia, numerous sovereign states in Africa, China, Ukraine (including Chernobyl), North Korea, Vietnam, Iraq, and Brazil.

[4] In his autobiography, he mentions that he never met his biological father and that he came from a poor family in ruined Yokohama; being born in a brothel as his mother was a prostitute for the Recreation and Amusement Association.

During an interview with Mainichi Shimbun, Akira stated that he was born with tuberculosis and that he never really thought about his biological father, believing that those who raised him were his real parents.

[5] He left the orphanage at the age of 16 and became a boxer (inspired by his childhood idol Hiroyuki Ebihara) to earn money, he then met his lifelong friend Rikiya Yasuoka, who was a kickboxer of Japanese-Sicilian heritage.

After a large brawl with members of the Zenkyoto in Hibiya Park in which he almost killed a man, the resulting police raid led him to an epiphany that "violence leads to nothing.

"[5] Yamanaka starred as himself in the Hollywood action movie Ulterior Motives featuring Thomas Ian Griffith and Ellen Crawford.

Joe recorded the entrance theme for Shinji Takehara titled "Hot Vibration" and composed the song "Sorrow of Florence" (哀しみのフローレンス) with his friend Amália Rodrigues.