A graduate of Koji Kitao's Bukō Dōjō, Masaaki spent the early part of his career wrestling for various promotions across Japan, namely WAR and BattlARTS. Most notable was his appearance in the 1995 Super J Cup, where he took on Shinjiro Otani of New Japan Pro Wrestling in the first round. Despite losing, Masaaki looked very competitive, using his sharp kicks and quick submission holds to pose a serious threat to the more experienced Otani.
In late 1999, Masaaki joined Toryumon, Último Dragón's upstart promotion, and quickly became recognized as one of the three "aces" of the company, alongside CIMA, and Magnum TOKYO. In April 2000, he formed the heel group M2K with Susumu Mochizuki (no relation), and Yasushi Kanda, the stable's name coming from their surnames. Darkness Dragon and Chocoball KOBE would join later in the year as well. The group wreaked havoc on Toryumon's initial El Numero Uno Tournament in 2001, forcing every group member's matches, except for Susumu's, to end in double-countouts. However, Masaaki won a second-chance battle royal to get back into the tournament. After defeating CIMA via knockout in the semi-finals, he pinned Magnum TOKYO in the finals; his only pinfall victory of the whole tournament. His issue with both, namely CIMA and his Crazy MAX stable, would continue through the end of the year; such was M2K's chicanery that Crazy MAX, the original renegade group of Toryumon, was turned face by default. After losing a hair vs. hair lumberjack match to CIMA in December 2001, Masaaki was humiliated into cleaning up M2K's act.
He returned in 2002, claiming to be a "good person", and made a conscious effort to rid M2K of its evil ways, something his stablemates would have none of; kicking him out of the group not long after. He would go on to lead the Toryumon Army with Dragon Kid and Ryo Saito throughout 2002. In 2003, he formed the much-maligned Shin M2K before a loss in December 2003 to fellow member Kenichiro Arai disbanded the group. At the beginning of 2004, he turned heel again to lead Aagan Iisou before, once again, his stablemates mutinied against him in April 2004. He was again a face, and former M2K members from both generations banded with him to form Final M2K as Toryumon became Dragon Gate.
In December, he celebrated 10 years in wrestling by defeating CIMA for Dragon Gate's top prize, the Open the Dream Gate Championship.
In December 2006, he won the 2nd King of Gate tournament, defeating Ryo Saito in the finals, and retired the M2K name forever not long after.
Mochi had an uneventful 2007.
In 2008, Mochi began teaming with Don Fujii, K-Ness and Magnitude Kishiwada, the team theme being that all the participants were over 30. Mochi and Fuji teamed in the Summer Tag League, but finished tied for last out of all the competing teams. On September 28, he, Fujii & Kishiwada won the Open the Triangle Gate Titles from Yasushi Kanda, YAMATO & Gamma.