Born in the Taitō ward of Tōkyō, Japan, he graduated from Komagome High School, and now belongs to the Asai Kikaku talent agency.
and physical comedy such as his distinctive "Kinchan run" (based on Hachiro Azuma) he blossomed into a polished professional.
However, after being told by Ōmiya "you can always come to our place if it doesn't work out there" he stopped at the last minute and went to nearby Tōyō Gekijō instead.
At Tōyō Gekijō, he took direction from many veterans such as Shin-ichi Ike, Eiji Ishida, and Hachiro Azuma.
After developing at Tōyō Gekijō, he moved to the affiliated Asakusa Furansu-Za, where he polished his act doing intermission skits.
During that time, he trained under broadcast writer Katsuo Hamaka and undertook the creation of true professional comedy.
During the time with Katsuo Hamaka, he was a friend of Shin-ichi Ichikawa, who would make his scriptwriting debut with the television series Kaijū Būsuka.
He would later write for the Nippon Television 40th anniversary special drama Goruden Boizu ("Golden Boys") in which a young Hagimoto appeared (with Kazuki Kosakai).
He formed the "Konto 55-gō" ("Skit #55") duo after an invitation from Jirō Sakagami in 1966, originally for a one-act contract (according to them, they had become a regular act without realizing it after renewing several times).
They became a sensation appearing on the live program Ohiru no goruden shō with Takehiko Maeda on Fuji Television (1968–71).
("birth of a star") (Nippon Television), where he developed a style of interacting with the family of guests and amateur extras.
(Kin doko) on Asahi in 1976 and "Kinchan no Shūkan Kin-yōbi" (TBS) in 1982, he picked up the nickname "100% Otoko", reflecting the sum of the ratings for the three shows.
Hagimoto is not only skilled at making ordinary performers into professional comedians, but also in drawing out the comedic side of celebrities.
Among those he developed into comedic starts includes Kiyoshi Maekawa (singer, previously a "cool" character actor), Hiroshi Uchiyama and Cool Five (mood ballad group), Rie Nakahara (young ballad singer), Junko Maya (formerly a stage actress), and Masaru Shiga (villain actor).
One example is Seiroku Saitō, who gained sudden fame appearing on Kin Doko, but was rarely seen on television afterward.
Aside from starring in and producing top-rate variety programs, he became the face of programs beginning with Sutā Tanjō (NTV) in 1971, continuing with Ōru stā Kazoku Taikō Utagassen (Fuji) as host, the still running 24-Jikan Terebi ("24 Hour Television") (NTV) from 1978, and also in radio on the Rajio Charitī Myūjikkuson ("Radio Charity Music-thon") (Nippon Hōsō) from 1975.
On the field before a game with Sega Sammy in Niigata Prefecture on July 22, he reversed his decision to break up the team.
", but when repealing the announcement he suddenly changed his tone, saying, "why you don't come out one night when there're no fans wearing a uniform with no number and hang out with us just as Yamamoto".
In 1971 Hagimoto met with Charlie Chaplin, who was living in seclusion in Switzerland at the time, for a Fuji Television production.
At the time, it was said that Chaplin would not meet anyone, and the production staff was uncertain whether it would actually happen, but a confident Hagimoto set off for Switzerland.
According to Hagimoto, the manager explained that various extortionists constantly visit the house so he refused unsolicited visitors access to Chaplin.
In December 1977 during the Nippon Broadcasting Rajio Charitī Myūjikkuson news of Chaplin's death was reported by Hagimoto, who spontaneously started crying.
According to his autobiography, he encountered no resistance from the press to his request, even receiving applause from the reporters at the time of the announcement, who were already aware of her background.
His influence on the entertainment and broadcast worlds can still be felt, with stars who started under him such as Tsutomu Sekine, Kazuki Kosakai, Emi Hashino, Toshirō Yanagiba, and Kunikazu Katsumata still appearing on television, radio, and stage, along with scriptwriters like Ryōichi Kimizuka and Shousuke Ōiwa.
However, after meeting with him in the dressing room, he dejectedly commented "[the act] was all just 'tennen' (natural)" (mindless foolishness rather than calculated comedic genius).
The game "yakyūken" in which the players play "jan ken pon" (rock-paper-scissors) while dancing to music and the loser takes off a piece of clothing, became well known after appearing on "Urabangumi wo buttobase!".
The "atchi muite hoi" extension of "jan ken pon" is said to have spread nationwide only after its use in Kinchan's spot on "Sutā Tanjō!".