 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.He is very close friends with fellow D-BOYS members Masato Wada (who often regards Kaji as a best friend and younger brother), Hiroki Suzuki, Osamu Adachi and Hirofumi Araki.On August 12, 2006, he, along with Hiroki Suzuki, attended the second performance showing in Tokyo for the "Advancement Side Rokkaku feat.