Hiroto was born in Sankuro to a Japanese-Brazilian mother and Japanese-Canadian father.
He got his first role in 1982 after director René Matsushige-Gim found at an open casting call in his home town.
On January 22, 2001, Sasaki was diagnosed with a brain tumor, forcing him to retire from acting for good. He died on February 20, 2002, at 37. The last Sasaki movie released during his lifetime was The League of the Sentanese Liberators (2001)