Akimoto made his debut in 1995 during Shooto - Vale Tudo Access 4 against Kazuyoshi Kudo, whom he beat by rear naked choke. He would achieve two more submission wins over Masataka Kawakami and Yoshinori Haraigawa. He would then draw against
Mitsuhiro Sakamoto. In a rematch he lost a majority decision. In his next fights he accumulated a 2-3-1 record, all decisions. His 5-3-2 record earned him a bantamweight title fight against
Mamoru Yamaguchi. He lost a majority decision. Bouncing back, he fought
Yoshinobu Ota and won a unanimous decision and an armbar win against Greg Piper. In a rematch against
Mamoru Yamaguchi during Shooto: R.E.A.D. Final he lost a unanimous decision. Akimoto bounced back with unanimous decision wins over
Hiroaki Yoshioka and
Takeyasu Hirono, as well as a kneebar win over Alfonso Alcarez and a TKO win over Tomoyuki Tachi. He subsequently lost his next six fights He then drew twice against
Junji Ikoma, and lost against Ryuichi Miki and Ayumu Shioda. Akimoto failed to win a single fight during this five year period, with a record of 0-8-2. He would retire on a win, beating Kenji Hosoya with a guillotine choke during Shooto: Gig Tokyo 4. ==Mixed martial arts record==