After training in the Último Dragón Gym, Senga made his pro wrestling debut in Toryumon Mexico on December 11, 2004, under his real name. After some events, Senga changed his ring name to Banana Senga and became a member of the salsa-themed heelstable Los Salseros Japoneses along his classmate Passion Hasegawa.
In 2006, he was moved to Michinoku Pro Wrestling, where he wrestled mainly in low-card matches. After the fall of Los Salseros, Senga was defeated by Ken45º and forced into his stable Ken Gundan, but the stable dissolved shortly after and Senga turned face, keeping his salsa mannerisms for comedic effect. Senga also played Shibaten, a kappa-based character, and had a feud with Rei. The gimmick lasted until 2009, when he adopted the gimmick of Yapper Man #1, taken from the animeYatterman.
El Dorado Wrestling (2006-2008)
When El Dorado Wrestling was created in 2006, Senga was brought in by his Toryumon comrades and formed an alliance with Toru Owashi. In 2007, Owashi, founded a stable called Animal Planets, which had an animal theme. Thus, Senga adopted the name of Hercules Oosenga, based on the Hercules Ookabuto, and started to wear beetle-like horns during his entrance. He feuded with Milanito Collection a.t. and defeated him in a backup dancers deprivation match, which caused a losing streak to Milanito and occasioned the loss of his gimmick, becoming Tsutomu Oosugi. After the Animal Planets demise in 2008, Senga changed his name to Hercules Senga and abandoned his beetle traits. He reconciled with Oosugi and formed a tag team with him, known as Speed of Sounds. The two proved to be a very successful duo, wrestling a high-speed style reminiscent of the Motor City Machine Guns or Paul London and Brian Kendrick. They were permanent fixtures on El Dorado cards until the promotion's closure in 2008.
While part of El Dorado, Hercules Oosenga started wrestling for Big Japan Pro Wrestling. Later as Speed of Sounds, they became a part of Mens Teioh's "Men's Club" junior cruiserweight matches, increasing their apparitions over the years until making the promotion their main field in 2015.
In 2010, Senga debuted in Pro Wrestling Noah as Ronin, a creepy samuraighost, and attacked Sugi after a match against Taiji Ishimori. The two had a heated feud both in Noah and AAA and toured Mexico. Ronin became an ally of Dark Family and had matches in All Japan Pro Wrestling, being defeated at the end by the returning Sugi.
