Animal Hamaguchi
Tetsuya Shimizu trained in the AJPW Dojo under Animal Hamaguchi as well as receiving extra training by Kaz Hayashi and Keiji Muto for his professional wrestling debut. Upon his debut he adopted the ring name T28, inspired by the Japanese manga "Tetsujin 28-go". Shimizu, as T28 wrestled his first match on March 12, 2007, losing to Nobukazu Hirai in the opening match of an All Japan Pro Wrestling (AJPW) show in Gunma, Japan. Only two months after making his debut, T28 participated in the "Tag Team Samurai! TV Cup Triple Arrow Tournament", teaming up with veterans Satoshi Kojima and Taiyō Kea. In the first round they defeated a team known as Grappler, Susumu, and Hanzo, before losing to Katsuhiko Nakajima, Kensuke Sasaki and Sanada in the second round. In February 2008, T28 teamed up with Kushida to participate in the U-30 Tag Team Tournament, a one night tournament that featured AJPW's top young wrestlers. The team defeated CJ Otis and Mototsugu Shimizu in the first round, Kaji Yamato and Taishi Takizawa in the second round and the team of Daichi Kakimoto and Manabu Soya in the finals to win the U30 Tag Team tournament. The team would go on to compete in AJPW's 2008 Junior Tag League, the team ended up tied for last place with only four points for two victories and three losses. He also competed in the 2008 AJPW Junior League, earning three points for one win and one time limit draw. In late 2008 it was announced that T28 would undertake a "learning excursion" to Mexico to help him gain international experience, a tradition for many young Japanese wrestlers. He wrestled his last match for AJPW on September 19 before travelling to Mexico.