Kaidō is mostly known for his "Snake Shot" (derived from the "Buggy Whip Shot"), a curving forehand that keeps his opponents running. He later develops the "Boomerang Snake," which is a shot that swerves out of bounds, around the net pole, and back in bounds. He developed the shot under mentor Sadaharu Inui's advice and by working with him in doubles. He usually plays the Singles 3 position, though he is most often placed in one of the Doubles slots.
In Genius 379, the last chapter of the manga, Kaidō is seen as a third year and the new captain of Seigaku, with Momoshiro as his vice-captain. Their rivalry has, apparently, somewhat mellowed with time. He lives with his brother, his mother, and his father. He and his brother bear a striking resemblance to their father.
Kaido wears bandanas. Mainly a green one while playing but has been shown to wear both a blue one, a yellow one, and a red one when training or simply off the court. He has short black hair and green eyes.In school when not wearing bandana, has a habit of praying before eating
Kaidō's nickname is "Mamushi", or the "Viper," which fits him well. He wears a bandana while playing tennis (in the anime, it is orange until episode 12 when it changes to green almost permentanly (only in a few, recreational episodes does it change color) and often exhales making a "fshuuuu" sound, similar to a snake. Kaidō does not like it when his nickname isn't taken seriously, and often reacts badly when called that within earshot by someone he doesn't like, especially if the person uttering the nickname is Takeshi Momoshiro or Akira Kamio (he once even comes to try hitting Kamio during the Fudomine matches, placing Tezuka in a rather uncomfortable situation). Despite his tough personality, Kaidō does have a soft spot for animals, as seen when he plays with Ryoma's cat Karupin in episode 27 and 73 and when he plays with a dog in episode 72. On the way to the finals against Rikkai Dai (episode 116-117), he leaps into a river to save a puppy.
Kaidō trains rigorously, increasing the training program given to him by Inui to give him unbeatable endurance. Both he and Takeshi Momoshiro are second year regulars and rivals. They constantly try to one-up each other, which is actually beneficial for the growth of their tennis skills; this makes them extremely powerful as a doubles pair, because the two rivals know each other so well.
Kaidō and Inui make an excellent doubles pair, mostly after beating Inui himself during the same line-up matches where Ryoma Echizen became a regular. Inui has seen Kaidō's potential and kind side and has taken him under his wing. In the fandom, they are often known as the "Emerald Pair." This is presumably a pun based on the name of Seigaku's "Golden Pair" (Eiji Kikumaru and Shūichirō Oishi) and the several green items associated with the Emerald Pair, such as Kaidō's bandana, Inui's notebook, Inui's special juices and pants he used when being the "training coach" of Seigaku after losing his regular place to Ryoma.
Kaidō is also shown to be timid and is scared of ghosts shown in episode 99 "Cursed Racket" he trys to run away when Inui tells them a horror story and Fuji scares everyone with a mask, and in episode 106 when arriving at the cottage.
Seigaku head into the District Tournament as favourites and cruise through to the finals against new upcoming team that are the surprise finalists, Fudomine Middle School. Kaido is placed in Singles 3 against fellow 2nd Year Kamio Akira. Kamio's speed gets the better of Kaido as he jumps out to a 5-3 lead. Kaido however refuses to give up and warns Kamio that the match is far from over. Kaido eventually climbs back and wins 7-5 thanks to his immense stamina.
Kaido and Seigaku head into the Prefecturals as the 2nd seed behind Hyotei. They somewhat comfortably advance past each of their opponents with their Quarterfinal opponents being St.Rudolph, another Tokyo school. In Doubles 2 against St.Rudolph in the Quarterfinals, Kaido pairs up with Momoshiro.
Just prior to the tournament he went to a Professional tournament which happened to be hosted by Japan and just so happened to be se sitting near a pair of Murigaoka students who were insulting both Rikkai Dai and Seigaku after hearing that Seigaku won the Nationals and heavily and coldly insulted Yukimura which greatly angered Kaido who overheard which resulted in a brawl which was stopped by the arrival of Yagyuu Hiroshi who explained that Kaido was in fact a regular at Seigaku and that he himself was a Rikkai regular and also that any Nationals players involved in violence would be punished.
The Murigaoka pair understand this and decide that they should settle their problems on the tennis court. Yagyuu and Kaido crush the pair however it is revealed that the pair had organised their school colleagues to record the match so if the situation arose in the Nationals they could prepare to shut down both Yagyuu or Kaido. However Yagyuu was one step ahead and had organised them to dress up as each other and play with swapped identities which meant they had to use each other's Special techniques.
After winning, switching back identities, Yagyuu then questioned Kaido what he would do if Snake was shut down before leaving.
Kaido went to the Nationals with Seigaku and his tournament began in Doubles 1 against Higa Chuu pair Shiranui Tomoya and Aragaki Kōichi. Kaido paired with Inui Sadaharu. However in answer to Yagyuu's question, Kaido decided that he would not use Snake during the whole match. He then gave himself another enourmous handicap by asking Inui to not play during the Doubles and allow a 2 on 1 game. Nevertheless, Kaido won 6-3 against Shiranui and Aragaki and with Seigaku winning 5-0 in the encounter between Higa they went through to the Quarterfinals with ease.
Kaido paired with Inui Sadaharu again for Doubles 2 against Hyotei and was fired up after watching Momoshiro Takeshi and Oshitari Yushi play a passionate match. The match was against Hiyoshi Wakashi and Mukahi Gakuto who are players that are low on stamina and specialise in quick matches. Mukahi begins the game by taunting Inui and Kaidoh arrogantly as he usually does to his opponents which gets the better of Kaidoh who swings at him, however Hiyoshi blocks and suppresses Kaidoh's racket threateningly and warns Kaidoh to calm down as the match is yet to start.
Hiyoshi/Mukahi begin by playing unlike their usual habits therefore Inui's data did not work for a total of 7 games. During those games, Kaidoh simply made all his shots have all of his power into them. Making them require more energy and stamina to return.
Hiyoshi and Mukahi waste energy and stamina by returning every shot that they get and constantly aim for winners. This tires them out drastically as the game count reaches 5-2 Match point. However, Kaidoh unveils his new technique Tornado Snake. Hiyoshi and Mukahi are unable to react to this and go back to their normal mannerisms as they had ran out of stamina. However, once back to their normal habits, Inui's Data Tennis took effect again immediately which meant Inui and Kaidoh took the score to a 7-5 win almost instantly.
Kaido paired with Momoshiro Takeshi in Doubles 2 against Shitenhouji pair Hitouji/Konjiki at the Semifnals of the Nationals. They play against the Idiot pair which consists of Hitouji Yuuji and Konjiki Koharu who are a homosexual couple and Doubles pair at the same time.
The two play what they call Comedy Tennis which completely throws off Momoshiro and Kaido off course time and time again during the match. However Kaido and Momoshiro refuse to give up despite being cornered by their opponents silly tennis. Eventually Momoshiro comes up with a plan to trick his opponents by wearing masks since their oppononents thought it was funny to play with wigs on. Thanks to wearing masks, the opponents are unable to tell who is Momoshiro and who is Kaido and they eventually win.
Kaido along with his Seigaku teammates recieves an invitation to the U-17 Camp due to the high quality of middle schoolers in this years tournament. He arrives at the camp with his teammates only to find that several other middle schoolers that the team have faced before are also invited to the camp. Kaido like all of the 50 middle schoolers invited is able to retrieve a ball that the helicopter drops which was the requirement to be allowed to stay in the camp.
Right after the first official shuffle match, having Momoshiro losing against Oni and resulting in having pain in both of his wrists, the mental coach for the U-17 camp appears: Saito. He asks all the present middle schoolers to pair up with whoever they want, leading them to believe they are to play a doubles pair, Kaido pairs up with Tezuka but right after the couples having been setted, the coach informs that every pairing will have to play against eachother. Saito also tells everyone that all the losers will have to leave right away after the match.
Tezuka takes seriously his match with Kaido, to the point to wanting achieve the goal to transmit him something important, but apparently ending up in an humiliant one-sided game, showing Kaido loosing.
All the losers get adressed to this bus, supposed to take them back home. While on the return trip the guys ask the driver a second chance, see themselves dropped right in front of this mountain where the coach Saito awaits for them together with Ryoma and Kintaro. All of them gets challenged to climb that mountain with nothing but their own hands, having the incentive to have a second chance and join again the U-17 camp if they'd succeed in this mission.
During the climb Momoshiro reaches his limits, still having an evident pain to both of his wrists, and right then, after an usual "encouragement" where Kaido tells him to be a coward if he gives up here for "just that", Kaido offers his help to bring Momo on his back while climbing. Somehow Momo accepts and Kaido starts to climb having his friend on the back. After a while Kaido also reached his limits by bringing a double weight, right when it was looking like a critical moment, Niou fakes "Keigo" and orders Kabaji to bring Momo on his back. All the losers show a really strong team's spirit wanting noone of them loosing here too and helping each other.
On the top of the mountain, Kaidoh meets the Drunken Coach who orders him and the other middle schoolers to do odd tasks. He trained in the mountains with the Drunken Coach with his extreme methods. Later on, the 27 middle schoolers in the mountains steal the Coach's sake, angering him to the point he decides they should all go back to the camp and start a revolution and come back with the other Middle School losers defeated and replaced the 2nd Court.
Kaidoh and the majority of the camp play audience to the match between Top 10 and their Middle School challengers and he and the data players comment on the players of the 1st match No.10 Mouri Juzaburou his former Rikkai teammate in the year above him and No.9 Ochi Tsukimitsu.
NOTE-1 Momoshiro (accidentally) knocked out Yanagisawa with a Dunk Smash that was hit off a slice lob, which caused the ball to change course and gave the Momo/Kaido pair the win, although Momo (tried to) protest.
NOTE-2 The match against Midoriyama only took place in the manga, while Josei Shonan's match existed only in the anime.
NOTE-3 In the anime, Echizen Ryoma took his place for Singles 3 and Kaido was Singles 2, so Kaido never got to play against Rokkaku.
NOTE-4 In the manga, the Momo/Kaido pair lost with the score of 1-6, while they lost in the anime with the score of 5-7.
NOTE-5 In the manga, the Momo/Kaido pair won with the score of 7-6 (unknown tiebreaker score), while they won in the anime with the score of 7-5.
Kaidō is a counterpuncher, noted by his stamina and retrieving most of the opponent's shot, using his physique to tire out his opponent first. While his play style becomes more aggressive as the series progresses, his original style is still evident in his matches.
A forehand or backhand shot that has an offset topspin that causes it to curve to the corners of the court, making the opponent run around and lose stamina. This is done by Kaidō shifting his weight from his right leg to his left and swings his racquet upwards while putting a lot of topspin on the ball with centrifugal force, making it go over the net in a crescent moon shaped fashion. The nature of this technique, however, makes this useless against Fuji's Tsubame Gaeshi, as noted by Kaidō himself.
In the anime, Snake is mostly depicted by a forehand, but in the manga, Kaidō uses a backhand Snake in his matches against Fudomine, Hyōtei, and Rokkaku. The only times a backhand Snake is shown in the anime is once in the Fudomine match, in stand-still shots in the matches against Hyōtei and Rikkai at the Regionals, and against Shitenhōji in the Nationals.
This is also called a Buggy Whip Shot, and is said to be used often by pros (i.e. Pete Sampras is mentioned to have used it). The Fudomine players refer to it as a Buggy Whip Shot in the manga as does Sadaharu Inui. In the anime, while Ryoma Echizen is playing Kaidō in the ranking matches, the turning point of the game is when Echizen realizes, and actually states, that the "Snake" is the Buggy Whip Shot. Sometime later, freshman Horio was also commenting on the excellence of Buggy Whip Shot, presumably when performed by Ryoma, much to the irritation of Kaidō.
Similar to the original Snake, the Boomerang Snake is a move from in which the tennis ball swings around the net in a sideways arch out of the court and back into the court on the other side instead of going over the net. It was initially performed by accident when he slipped while diving for the ball against Fudomine'sAkira Kamio. Kaidō kept trying to use it after that, but the ball continually went into the alley, which in singles is out. It was still effective when playing doubles, where the alleys are counted as in, and it shocked all who were both in the game and watching it. The ref was even startled as it flew just below his chair. After that, Kaidō needed to spend a lot of time training in order to hit it properly during a singles match for it to count. Kaidō finally perfected the shot at the Kantō conference playing doubles with Inui against Hyōtei'sChōtarō Ootori and Ryō Shishidō.
A variation of the Snake shot which has a much greater curve than the original. Instead of going deep into the corners, the Short Snake uses the curve to get around the net player. Kaidō first uses this move in his doubles match with Momoshiro against Bunta Marui and Kuwahara Jackal of Rikkai Daigaku Fuzoku to break Marui's net play.
A Snake Shot that goes in the opposite direction of a normal Snake Shot. Kaidō develops this shot in order to prevent Jackal Kuwahara from guessing where his shots were going and running to the corners before he even hit the shot.
Yet another variation of the Snake, the Tornado Snake has a gyro spin version. Kaidō hits the ball with an upward facing backspin of a Magnus power and travel direction against a spin axis with a 45 degree entry angle. Because it's spinning, the ball barely receives any air resistance. Due to the spin, it's about 0.03 seconds faster than any other straight ball, as all noted by Konjiki Koharu of Shitenhōji. Kaidō first uses this technique at Nationals in the doubles match against Hyōtei, which he and Inui defeat Wakashi Hioyshi and Gakuto Mukahi. There are also different variations of the Tornado Snake.
Formerly known as the "Laser Beam", this is an extremely fast forehand shot developed by Hiroshi Yagyū of Rikkai Daigaku Fuzoku. When Kaidō and Yagyū play an unofficial doubles match against a pair from Murigaoka, they disguise themselves as each other and each hit each others signature shots. Afterwards he asks Inui to help him hit the Laser Beam using the same form as the Tornado Snake. This technique makes its true debut against the Yanagi/Kirihara Pair. He adds in the same gyro spin as he would to the Snake Shot that makes his Laser Beam faster than Yagyū's. It was said by Inui that if Kaidō could hit Laser Beam using the same form as Tornado Snake it could confuse his opponent on which would come and that he might become invincible.
The Jack Knife, which is one of the signature shots of Kaidō's rival, Takeshi Momoshiro, is a very high level backhand shot in which the person hitting it jumps off the ground with their left foot. It is not only powerful, but fast as well, and it was stated a normal Junior High School student wouldn't be able to keep up with it.
While disguised, Kaidō and Momoshiro play against Hitōji and Konjiki of Shitenhōji. Kaidō hits the Jack Knife in order to cause the opponents to think he and Momoshiro had switched places.
This technique is similar to Kirihara's expanded Bloodshot Mode. Kaidō activates this state when Kirihara continuous hits the ball causing more injuries to his respective senior, Inui, during the national final D2 match. However, Inui is able to snap him out of this state.
This is a combination of the Hadoukyu technique and Boomerang Snake. The shot moves like Boomerang Snake shot, but it is very powerful and can knock the opponents racket out of their hand. Although the one-handed Hadoukyu is considered to be dangerous due to straining the arm, Kaidō is seen to have no problem using the one-handed shot for his Boomerang.
In the Prince of Tennis Musicals, Kaido has been portrayed by actors Naoya Gomoto (2003-2005), Kousuke Kujirai (2005-2006), Tomo Yanagishita (2006-2008), Yuuichirou Hirata (2008-2009), Akihiro Hayashi (2008-2010), and Ryousuke Ikeoka (2011-present). Kousuke Kujirai potrayed Kaido in the live-action adaptation film.
Although most of his teammates are unaware of this, Kaidoh loves animals.
A Running Gag about Kaidoh shows that he actually is afraid of ghosts and horror related stories. (See ep. 99 "The Cursed Racket", 106 "Off to the Cottage"..)
Edit
Added by Teomin89
Added by Airgrimes
