|This article is about a/an producer in the Kamen Rider Series.|
|Born||March 19, 1929|
|Born in||Nagoya, Aichi Prefecture, Japan|
|Died||July 31, 2013 (aged 84)|
|Died in||Sayama, Saitama Prefecture, Japan|
|Role(s)||producer for Kamen Rider Series|
In 1969, Shotaro Ishinomori, who was a known face in tokusatsu industry at the time, was approached by Hirayama to have his Skull Man manga adapted for the Masked Hero Project. Originally the project was rejected due to criticisms that it was too violent for the timeslot it was given.
After the duo reworked the story and designs, the final Kamen Rider design, a Grasshopper, was chosen by Ishinomori's son. This drawing would go on to become the original Kamen Rider 1, after some modification. The hero Takeshi Hongo, portrayed by actor and stuntman Hiroshi Fujioka, was described as a transformed human (改造人間 kaizō ningen?), or cyborg. Eventually, Kamen Rider, the original series, premiered on April 3, 1971.
On July 31, 2013 Hirayama passed away from heart failure at the age of 84.