He has fair skin and is a slimming man, but is a stubborn person with a dirty mouth. After his match with Oni, he was sent to the Medical Center and is now essentially retired.
Kaji has long shoulder length hair and has a tear mole.
U-17 Camp Revolution
Kaji is first seen on the 1st Stringer's coach arriving from their Foreign Expedition as the All-Japan Junior No.5, agreeing with the twins Mutsu Yuuma and Mutsu Yuuho that the sound of the 2nd Stringers playing tennis could be heard nearby. Representative No.1 Byoudouin Houou then tells No.s 11-20 to have as much fun as they like against their 2nd Stringer challengers and the Top 10 representatives make their way to the main courts expecting to meet up with the No.s 11-20 later.
He is then seen with the rest of the Top 10 members of the 1st Stringers arriving at the main courts where the rest of the camp await to hear the results of the other 1st Stringers matches of their challenges from the 2nd Stringers in the Camp's Foreign Expedition Group Challenge. He along with the rest of the camp are shocked to see Middle Schoolers return instead of the rest of the Top 20 as the camp find out that No.s 11-19 are replaced by Middle Schoolers.
Kaji and Oni Juujiro then have a match for the No.5 position in the evening revealing that Kaji was only the temporary No.5 and that Oni was the inital No.5. Oni completely overwhelms him quickly and takes back his badge back making Kaji a 2nd Stringer.
Playing Style and Techniques
U-17 Stats 
Speed - 7: He has absolute faith in his speed, but when faced with the presence of Oni, he had no ability to answer him because he could not see through to his real level.
Power - 5: His power is average. While away on the expedition, it seems his power rose considerably, however in his match with Oni, it was completely useless.
Stamina - 5: Before the expidition, Stamina was an insufficiency he was tasked to work on. However, after he returned home, it seemed he has conquered this problem. However, his body fat percentage seems to have increased some. It would seem while he was abroad, he destroyed his body balance through poor eating habits.
Mental - 4: He has an keen perception, but on the other hand, his weakness is that his power of concentration drops when faced against an opponent he isn't suited for.
Technique - 5: He has a vast array of skills in his repertoire. While on the expedition, it seems like he worked out a new technique too. However, he was defeated before ever being able to show it.
Personal Information 
- Hobbies: Flower Divination
- Comittee: Library Comittee
- Favorite Color: Wheat Color
- Favorite Food: Marshmallows
- Thing he wants most: Hair Wax
- Thing You're Bad At: Noise
- Specialty outside of Tennis: Divination
- His fluffy hair is naturally curly. If you try to comb his hair, he gets mad.
- He was sent to the Medical Center after his match with Oni, and considered retired.
- Kaji is the fastest player in the U-17 Camp.
- Kaji Kazena and Atobe Keigo are the only players that have 'tear moles'.
- Kazena is listed as a 3rd year Middle Schooler in the manga, upon his first appearance. This might have been a typo.