Shūji Tanegashima is a laid-back and free-spirited individual who seems to approach everything with a sense of amusement. He enjoys observing matches rather than actively training, as seen when Tokugawa Kazuya noted that Tanegashima appeared to be having fun simply watching the middle schoolers defeat several high schoolers.

Despite his relaxed demeanor, Tanegashima has a sharp wit and a mischievous side, frequently teasing and trolling his teammates, particularly Sanada Genichirō. His playful nature extends beyond words, as he is often seen riding around on a Segway, further reinforcing his carefree attitude. However, this lack of visible effort belies his incredible skill.

One of Tanegashima’s most notorious traits is his ability to read opponents perfectly, allowing him to predict their movements with absolute accuracy, making his “Look Over There” trick nearly impossible to counter. Unlike ordinary players who rely on guesswork or intuition, Tanegashima seemingly always knows where his opponents will move.

Beneath his lighthearted and sometimes lazy exterior, Tanegashima is highly perceptive and aware of his surroundings. This is demonstrated when Irie Kanata feigned an injury after his gruelling singles match against Atobe Keigo. While others were fooled, Tanegashima easily saw through the deception, tossing Irie a towel in the changing room and prompting him to instinctively catch it with his supposedly injured left arm, exposing his lie.

Shūji Tanegashima is a tall and slender young man with distinctive white wavy hair, which sets him apart from most other players. His most notable feature is his dark skin tone, which is even darker than that of players from Kyushu, who are typically depicted as having slightly tanned complexions.

In the anime adaptation, Tanegashima is shown to have purple eyes, adding to his unique and somewhat enigmatic presence. However, in the manga, his eye color is brown. His casual and carefree personality is reflected in his relaxed posture and effortless movements, often appearing as though he is barely exerting himself, even when engaging in serious matches.

Shūji Tanegashima was initially perceived as just another strong 2nd Stringer at the U-17 Training Camp. However, it was later revealed that he was actually a 1st Stringer and held the prestigious No. 2 position among the All-Japan Junior Representatives, making him one of the most formidable players in the entire camp.

Despite his high-ranking status, Tanegashima did not participate in the team’s foreign expedition because of his hatred of airplanes, opting to remain at the camp while the other Genius 10 players traveled abroad. His decision to stay behind reinforced his carefree and laid-back nature, but his overwhelming skill level made it clear that he was still among the strongest players in Japan.

Tanegashima was first introduced as a member of the 1st Court, watching the middle schoolers defeat high school opponents and steadily advance up the rankings to the 5th and 6th Courts. Tokugawa Kazuya noted that Tanegashima seemed to be enjoying watching the younger players progress.

Later, during the Team Shuffle between the 5th Court and the 3rd Court, Tanegashima was revealed to be part of the 1st Stringers and held the No. 2 ranking among Japan’s All-Junior Representatives. Unlike the other top players, he had not participated in the foreign expedition due to his hatred of airplanes.

Tanegashima was present with the other 2nd Stringers upon the arrival of the Top 10. When Echizen Ryoma noticed that only nine players had arrived, Tanegashima casually pulled his 1st Stringer jersey from his bag and put on his No. 2 badge, revealing his true status to the middle schoolers. He then lined up alongside the rest of the Top 10 to take on the 2nd Stringers in the Foreign Expedition Group Challenge.

After learning that the No. 11-20 players had been replaced, and that middle schoolers had defeated the No. 11-19 players, the Top 10 found this to be a disgrace. In response, Kimijima Ikuto (No. 7) decided to set up a rota for the Top 10 matches, including the middle school challengers.

Tanegashima’s playful nature emerged when he stole the drink of a thirsty Kaidoh Kaoru, who had been jogging and needed to hydrate. When Sanada Genichiro reassured Kaidoh that his drink was nearby, Tanegashima took Sanada’s drink as well, infuriating both middle schoolers.

The next day, Tanegashima and the rest of the Top 10 watched from the sidelines as the camp witnessed matches between the Top 10 and the Middle School challengers.

After the Top 10 lost one match but won three straight, Tanegashima and No. 6 Ohmagari Ryuuji stepped up to face Sanada Genichiro and Jin Akutsu in a Doubles match. The match started at an extremely fast pace, with Sanada unleashing his special attacks and Akutsu playing aggressively. However, Tanegashima stunned everyone by effortlessly returning all of Sanada’s moves and even reflecting Rai back onto Sanada, breaking his racket strings.

Tanegashima then toyed with Sanada, deliberately faulting his serve and knocking Sanada’s water bottle to the ground. He further agitated Sanada by handing his racket to Ohmagari Ryuuji and sitting down while Ohmagari played alone, handling both Akutsu and Sanada with ease.

However, this didn’t last long, as Sanada revealed his perfected Black Aura, forcing Tanegashima to rejoin the match. Taking his racket back, Tanegashima nullified Sanada’s Black Aura shot in a single play. The roles then reversed, with Tanegashima playing solo against Sanada and Akutsu, just as Ohmagari had done earlier.

Towards the end of the match, Sanada shocked everyone by unveiling a Double Clutch version of his Black Aura shot, causing the ball to change direction twice at high speed, catching even Tanegashima off guard. However, this was not yet perfected, allowing Tanegashima and Ohmagari to cruise to victory.

Coach Mifune took both high school and middle school representatives to a beach and tasked them with picking up girls. Tanegashima, riding his segway, successfully charmed a girl. However, since using the segway was considered cheating, it was confiscated, causing Tanegashima to fail the challenge. While the Japanese representatives traveled to Australia to prepare for the World Cup, Tanegashima was not with them, as he traveled by ship instead.

Tanegashima was assigned as the team leader against Greece and was scheduled to play Singles 1. However, upon seeing Shiraishi freeze up in fear of his opponent, Tanegashima stepped in.

His opponent, Zeus, completely dominated Tanegashima, winning five straight games. However, Tanegashima adapted by attaching a bottle cap to the bottom of his racket, making his shots completely unpredictable, even to himself. This prevented Zeus from controlling the match’s pace, allowing Tanegashima to win the next seven games and secure victory.

Despite his win, he was scolded by Byodoin for using unconventional tactics.

Tanegashima Shūji is a highly skilled defensive tennis player with an unconventional style that often confounds his opponents. Despite being right-handed, he plays in a unique manner, removing his left arm from his jacket while keeping it half-zipped, causing part of it to hang behind him. This seemingly relaxed and carefree stance contrasts with his exceptional ability to return powerful shots effortlessly, even those that could break an opponent’s racket. As the No. 2 ranked player in Japan, his defensive mastery and unpredictable techniques make him a formidable opponent in the U-17 camp.

Tanegashima’s abilities are so exceptional that even Oni Jūjirō, a player known for his monstrous strength, admits that he has never been able to defeat Tanegashima. However, Tanegashima, in his usual easygoing manner, humbly responds that he has also never won against Oni. His skills lie in negating an opponent’s offensive plays, making it nearly impossible to overpower him with sheer force.

One of Tanegashima’s most remarkable abilities is Halt Destruction Nothingness, which allows him to instantly perceive and nullify the effects of nearly any special shot. His unmatched reflexes enable him to effortlessly return even the fastest and most powerful moves, such as Sanada’s Lightning and Black Aura shots, without sustaining any damage to his racket. His technique, Flash Tennis, takes this unpredictability further by voiding his own mind, making his returns completely random and impossible for opponents to anticipate.

Among his most deceptive techniques is Void Before Birth, a lob shot that stalls in the air for a brief moment, throwing off the opponent’s timing and disrupting their rhythm. His Ultimate Void technique enables him to erase his own presence on the court, making it nearly impossible for opponents to track his movements. Even more astonishing is his Reciprocal Void, which extends this ability to his doubles partner, effectively making them invisible to the opponent’s awareness. This technique played a crucial role in his victory against Germany when he paired with Akaya Kirihara, as their opponents struggled to react to the disappearing presence of his teammate.

As a player, Tanegashima does not rely on raw strength, but instead excels in stamina, strategy, and psychological manipulation. His playstyle is infuriating to aggressive opponents, as he effortlessly deflects their strongest shots, forcing them into frustration and exhaustion. His ability to read and predict an opponent’s weaknesses allows him to control the pace of a match with ease.

Despite his immense talent, Tanegashima is known for his carefree personality and playful nature, often taunting his opponents and teammates alike. He enjoys trolling Sanada, frustrating him to no end, and is frequently seen riding around on a Segway rather than actively training like the rest of the team. However, his natural perception and wide field of vision, honed by constantly tracking high-speed movement, make him one of the most formidable and unpredictable players in the U-17 tournament.

While his mental flexibility and strategic insight give him an edge in battle, Tanegashima’s one major flaw is his moody nature. He only plays seriously when he feels like it, and in real matches, he sometimes recklessly shows off, which can put him at a disadvantage if he underestimates his opponent. Despite this, his talent is undeniable, and his ability to counter even the strongest attacks makes him a key player in the Japanese U-17 team.