Then on January 1, 2007, Kaji appeared again on the New Year's Day 44th annual broadcast of the Secret New Years' Performance Tournament's "Chinese Lion Dance" segment, with Hiroki Suzuki and fellow D-Boys members, Yuya Endo, Masato Wada and former D-BOYS member, Yuuma Minakawa.
The D-BOYS have also starred in their own drama documentary variety series called, DD-Boys[2] in which Kaji's appeared in a few episodes as himself.
Since his graduation, the role of Momoshiro has been played by Shinpei Takagi, by fellow D-BOYS member Tetsuya Makita, and by actor Toshihiro Nobeyama.
The Prince of Tennis was released on May 13, 2006, and opened on the tenth spot in the Japanese box office and marked Kaji's first major film debut.
Later, Kaji and his costars (under ROM-4) recorded and released the CD single called "Keep It Goin' On", which was used as the show's ending theme.
The show revolved around a university rowing club, in which Kaji had the role of playing the freshman, Toshiyuki Hoshino, on the team.
The cast features Kaji's former Tenimyu co-actors, Kamakari Kenta and KENN, reprising their voice-over roles from the anime respectively as Ikki and Kazu, with RUN&GUN, Kenjiro Tsuda etc.
Other cast members also include Jun Nagura, Ken Horiuchi, Chiaki Hara, Asami Abe, Rag Fair etc.
Kaji will once again act alongside fellow D-Boys member, Yuu Shirota, as well as be reunited with former Tenimyu castmates, Kousuke Kujirai, Yoshikazu Kotani, and Musical Air Gear co-star, Kenta Kamakari.
Previously, in 1998, a live-action TV series had been made titled Shin Shōnan Bakusōzoku Arakure Knight (Bomber Bikers of Shonan).
The movie is an adaptation of Gettsu Itaya's semi-autobiographical novel, Waruboro, and is set to be released in the summer of 2007 as principal filmography began on September 20, 2006.
In his blog entries he likes to call himself "Karaage" (literally meaning "fried thing"), which is a running joke between him and Hiroki Suzuki, due to Kaji's dislike for his tan.
On August 12, 2006, he, along with Hiroki Suzuki, attended the second performance showing in Tokyo for the Advancement Side Rokkaku feat.
TENIMYU: The Prince Of Tennis Musical Series (as Takeshi Momoshiro) Kaji has currently released a CD Single on June 21, 2006, called "Keep It Goin' ON" with fellow members, ROM-4.