Born with the name Masayoshi Kato, Kenji Sahara has had a long film career. He is best known for his work in Toho's science fiction productions. The actor is one of the few actors to have appeared in the Showa, Heisei and Millennium series of the Godzilla franchise.

Sahara first got his break in the business back in 1953 at age 21. This break came with placing second in the "Mr. Ordinary Contest", with first place going to future Nikkatsu star Ryoji Hayama. Seeing talent, Toho immediately placed Sahara in the "Toho Acting Institute". Following his graduation, Toho signed the actor to an exclusive contract. The very next year he started appearing in productions. These included small parts in Farewell Rabaul (1954) and Godzilla (1954). At this time, he was using the stage name of "Tadashi Ishihara".

In 1956, Sahara's career really launched. Changing his stage name to "Kenji Sahara", the actor landed the lead role in the high profile film Rodan (1956). This followed with another leading real the next year in The Mysterians (1957). These performances cemented Sahara as the go-to choice to play the "salary man" role in Toho's early science fiction productions.

In 1963, Sahara would break out of his type casting and start to play villanious roles as well. This includes a great transformation as the seedy Senzo Koyama in Matango (1963) and as an invading race in Atragon (1963). The following year, while working on the joint production None But the Brave (1965), Sahara developed a solid relationship with special effects director Eiji Tsuburaya while filming on location in Hawaii. This paved way to the actor taking the staring role in Tsuburaya's Ultra Q TV series, which lead the way for Ultraman.

It's no shock that Sahara had developed a reputation for his science fiction work, and continued to be cast in the special effects productions of Toho. The nature of his screen presence though had drifted to supporting. After a long career at Toho, Sahara left the company in 1976 to do work for other studios. This ended up being temporary, as when Toho relaunched the Godzilla series they picked on Sahara to have small roles in films like Godzilla vs. King Ghidorah (1991) and Godzilla vs. SpaceGodzilla (1994).