Strudolph mizuki
Hajime Mizuki



Mizuki Hajime






166 cm


52 kg


May 27



Eyesight (Unaided)

1.0 (both eyes)

Blood Type



Two Older Sisters

Junior High

St. Rudolph (3rd year)



Club Position


Elementary School

North Zaou Elementary School (Yamagata Prefecture)

Japan U-17 Camp

Court 9

Dominant Arm


Play Style

All Rounder


Yonex Muscle Power 7


Prince Quicktrack Ti in navy


Atobe's Gift

Voice Actor

Akira Ishida (Japanese)
Steve Staley (English)

Hajime Mizuki (観月はじめ, Mizuki Hajime) is the St. Rudolph's manager.


Hajime Mizuki is a brilliant tennis player who can map out a tennis match in his head that usually has a high success rate after factoring in the enemy players and his team member's capabilities. He was the one who recruited Yūta Fuji and Atsushi Kisarazu for the St.Rudolph Tennis Team, although Atsushi's recruitment was more of an accident, as he was planning to recruit his twin brother instead.


He has vivid purple hair which he often twirls around his finger and brown eyes. In the anime he has dark blue/black hair, and dark blue eyes.


Mizuki makes a good manager, but he isn't a very good teammate. He is willing to sacrifice the health of his teammates for the himself (training Yūta Fuji to use the dangerous Twist Spin Shot). He is extremely cunning and calculating. He believes that with enough data, the game will be paced as he planned and because of this, when a teammate loses, he places the blame on his teammate not properly following his advice. Because of this, he is highly critical of anyone that loses, from blatantly telling Atsushi (in the anime) that he embarrassed the team to outright ignoring Yuta. Data Tennis is Mizuki's pride, but during the matches against Shūsuke Fuji and Keigo Atobe, the cocky Mizuki was shown that data was not flawless.

Albeit, being a very shrewed person, Mizuki also has a quirky side to him. He likes to spy on other tennis teams during his own time and calls it collecting data. Mizuki will often come up with elaborate and crazy plans in order to fulfill his goals (often dragging some of his teammates against their will into it, especially Yuuta). Despite his careful personality, Mizuki can often get side-tracked and stray from his original purpose very easily, while acting as the deviation was fully intended. Mizuki also cares a lot about winnng so whenever someone mentions that his team lost this match or did not get into Nationals, Mizuki would get fairly depressed (usually portrayed in a comical fashion).

Mizuki depressed

Mizuki's face after being reminded that he did not get into Nationals.

However, in the end, everything Mizuki did was for the benefit of his team as a whole, whether it was for scouting new recruits to collecting data. He is able to learn the errors of his ways soon enough and is able to become a proper teammate that genuinely cares for the well-being of his team.


One Year Prior To The Storyline

He recruited Yūta by the time he transferred out and uses this to his advantage, further fueling the bitterness Yūta felt toward his older brother.

  • Playing with his hair
  • Mizuki blushing due to Yumiko (Fuji's sister) beautyGo to
  • St.Rudolph (awkwardly) spying on Yuuta

Tokyo Prefecturals

In turn, Mizuki taught him the Twist Spin Shot which could end his tennis career if used with an immature arm muscles and joints and Yūta was indeed immature in his playing arm, but could execute the skill with proficiency. Ryoma Echizen pointed out the drawback in his technique and Shūsuke Fuji and Sumire Ryūzaki hearing it was shocked, and Shūsuke Fuji was downright furious. Fuji got his revenge by letting Mizuki think he wasn't any good and let Mizuki win a couple games, and then became an awakened lion and beat him in minutes flat in full level, humiliating him thoroughly. Since then, Mizuki disliked Fuji though he began training Yūta seriously, or Sadaharu Inui style and proclaimed him 'his disciple'.

Mizuki in action

Mizuki in action against Fuji Shusuke.

After Seigaku knocked St.Rudolph out of the Tournament, they faced Hyotei for the 5th place Consolation match and was defeated by Hyotei with Mizuki getting crushed by Keigo Atobe 6-0. This meant that Hyotei took the last spot to go to the Regionals and St.Rudolph's tournament journey ended abruptly.


Mizuki was seen with his teammates at the Kanto Regional Final between Seishun Gakuen and Rikkai Daigaku Fuzoku.


Mizuki and Fuji Yuuta watched the Semifinal match between Seigaku and Shitenhoji.

U-17 Camp

Mizuki Hajime and St.Rudolph teammate Fuji Yuuta are the only members of the School to be invited to the U-17 Training Camp and were also the only middle schoolers that were from a school that did not make it to the Nationals.

At the camp, Mizuki and all the other middle schoolers are tricked into playing a doubles tie-breaker style game against their friends. He is then drawn in a tie-break game against fellow Data Tennis user Inui Sadaharu. Fortunately for Mizuki, he does not have to play as Inui forfeits due to making a mistake in the ingredients of his Inui Juice giving him a stomach ache.

Mizuki's first match at the U-17 Camp was as a member of Court 13 against a 6th Court member which he lost which is revealed in Pair Puri Vol. 4. He later advances to the 9th Court.

Tennis Record

Playing Styles and Techniques

Mizuki is an All-Rounder and a Data Tennis player. His main strategy is to aim at his opponent's weak points and shut them down quickly. The nature of his play style is carried over to his training regimen, where he creates practice exercises for his teammates to counter their opponent's strengths. His training regimen was popular enough to even be praised by high schoolers in the U-17 camp. Mizuki is also shown to have good control, as he is able to hit shots towards the opponent's (perceived) weak points precisely. However, his biggest flaw is his overconfidence in his data; in two occasions it was shown that the data he collected was not as accurate as he believed and he was unable to keep up with higher level players, as shown against Fuji and Atobe.

Data Tennis (データテニス)

A style of tennis based on gathering data on the opponents. By using his extensive research of opponents, Mizuki is able to mentally simulate the course of the match, and at times, it seems to be accurate enough to even predict the final score of the match. On-court, his primary usage of Data Tennis is to aim his shots towards what he believes would be the opponent's weak points.

Mizuki's Data Tennis has also shown to be of help to others besides himself, as he had the St. Rudolph coach train Yanagisawa and Kisarazu to return off-angle shots like Snake and personally taught Yuta the Twist Spin Shot and later helped Yuta develop the Double Twist Spin Shot.

However, his Data Tennis is also his biggest flaw, as he believed that he had perfectly gained Fuji Shusuke's data when Fuji was actually hiding his limits. His data on Atobe was also proven to be useless, as Atobe crushed him with relative ease despite the information he collected against him due to the difference in skill level.

U-17 Camp Stats

  • Speed: 2
  • Technique: 4
  • Mental: 4
  • Stamina: 3
  • Power: 2

Personal Information

  • Favourite Food: Vichyssoise; Capellini pasta topped with caviar.
  • Hobby: choosing black tea leaves
  • Favourite Color: pure white
  • Best Subject: Japanese, English, French and Spanish.
  • Worst Subject: calligraphy as "his hands get dirty".
  • His fathers occupation: 'Enka singer' and 'Agriculturalist'.
  • Foot Size: 26.5.
  • Committee: Dormitory Administration Committee.
  • Motto:「敵を知り己を知らば百戦危うからず」, originally from Sun Tzu, it translates as "If you know the enemy and you know yourself, you need not fear the result of 100 battles".
  • Favourite Movie: Breakfast at Tiffany's (film).
  • Favourite Book: chemistry/science books.
  • Favourite Music: "Yepes guitar albums".
  • Dislikes/Bad at: dirty things, and dust and pollen due to allergies.
  • Most frequented parts of the school: the library and the reference room.
  • Favorite Type: 'no particular preference' followed by the quote 「そんなこと聞いてどうするんですか?」, meaning roughly "what would you do if I told you that?"
  • Favorite Date: a stylish cafe in the style of the British royalty.
  • Spends Allowance On: tableware and food.
  • His most wanted item: a Rococo style tea set.
  • Daily routine: keeping a "rose observation diary".
  • Special Skill outside of tennis: singing opera.
  • The number of personal computers he has purchased is 6.


Character Trivia

  • Mizuki fainted after Kenya's pet Iguna suddenly jump on his head while playing ping pong with Kikumaru. [1]
  • Mizuki is highly skilled at ping pong/table tennis, and even has his own personal paddle, since he has been playing ping pong since elementary school and was a member of the national champion ping pong team during that time. [1]


  • (In response to Fuji’s refusal of a handshake and his expression) “Oh dear, that’s quite a scary face.” (Oya oya, zuibun kowai ka wo desu ne.”)
  • “Let’s have a good game.” (“Ii game ni shima sho.”)
  • “Nfufufufu.”
  • “Fuji Shusuke, you’re strong for certain. But you can’t win against me.” (“Fuji Shusuke, kimi wa tashikani tsuyoi. Demo boku no wa kate nai.”)
  • “I can see it all, Fuji-kun. All your weak points!” (“Maru mie desu yo, Fuji-kun. Kimi no jyaku ten ga!”)
  • “From this course, just try to return it!” (“Sono course, kaeshite miro!”)
  • “It’s meaningless if we don’t win!” (“Kata nake imi ga nain da!”)