TV-Series
Description
Itsuki Takeuchi is a central supporting character, best known as the best friend and high school classmate of the protagonist, Takumi Fujiwara. He works part-time at a gas station, the same Esso station where both Takumi and his senior, Koichiro Iketani, are employed. This job is his primary source of income, and he saves his earnings with one major goal in mind: to purchase his own car. His ambition leads him to acquire a white Toyota Corolla Levin. However, in his eagerness, he makes a critical mistake, buying the inferior AE85 model (often called the Eight-Five) because he mistakenly believes it to be the more powerful and desirable AE86 (Eight-Six) that Takumi drives. This error becomes a source of embarrassment and mockery from other racers, but it also serves as an important learning experience.

In terms of personality, Itsuki is loud, obnoxious, and highly emotional, often serving as the primary source of comic relief within the series. He is endlessly enthusiastic about street racing and cars in general, despite his own lack of experience and knowledge. He is quick to brag and gets easily excited, but he is also just as quick to become dejected, especially when his mistakes or lack of skill are pointed out. Underneath his bravado, he is a loyal and good-hearted individual who, despite his envy of Takumi's natural talent, never stops cheering for his friend. He admires Takumi's abilities immensely and dreams of one day being a skilled racer himself. A unique personal detail is his stated preference for Taiwanese bananas and his strong dislike for front-wheel drive cars, automatic transmissions, and diesel engines. Physically, he is described as being approximately 162 to 163 centimeters tall and weighing around 55 kilograms.

Itsuki's primary motivation throughout the story is his desire to be a recognized and capable street racer. Initially, this manifests as a desire to simply own an Eight-Six to form a duo with Takumi. After his disappointing purchase of the AE85, his motivation shifts towards proving that his car, and by extension himself, is not a joke. He is driven by a need for respect and a wish to emulate his best friend's success. Takumi encourages him by demonstrating that driver skill is more important than the car's specifications, a lesson that becomes the foundation of Itsuki's approach to driving.

His role in the narrative is multifaceted. Most importantly, he is Takumi's confidant and anchor to a normal life outside of the intense world of Project D and professional racing. Their friendship dates back to middle school, and Itsuki is one of the few people who understands Takumi's personality and thoughts. He is also a member of the local team, the Akina SpeedStars, and looks up to Iketani as a senior. Itsuki often acts as a catalyst for events, most notably when he inadvertently accepts a race challenge from Takeshi Nakazato of the Myogi NightKids on Takumi's behalf. His relationships are not always successful; he has a couple of notable romantic interests, including a girl named Saori, who ends their relationship after a traumatic car accident caused by rival racer Shingo Shoji, and later Kazumi Akiyama, who briefly teaches him how to drift but ultimately leaves him.

Throughout the series, and specifically looking at the timeline that includes Fourth Stage, Itsuki shows notable development. He transitions from being a completely inexperienced and reckless dreamer to a more serious and competent driver. He begins to practice drifting earnestly, receiving tips from Iketani and even learning from Kazumi. A key milestone in his journey is when he uses his first paycheck from his job to install a turbocharger in his AE85, boosting its horsepower to 150. This upgrade, featured as a major moment, shows his commitment to improving his machine and his skills. He is seen performing powerslides and keeping pace with more experienced drivers, demonstrating a clear, though gradual, improvement behind the wheel.

Itsuki's driving abilities are initially characterized by aggression and a severe lack of experience, often leading to mistakes. However, he proves to be a capable learner. After instruction, he manages to successfully execute power-slides in his turbocharged AE85. While he never reaches the level of a prodigy like Takumi, he develops into a competent amateur driver who can handle his car with confidence. His true strength lies not in his driving, but in his unwavering faith and intuition. On several occasions, even when logic suggests Takumi cannot win a race, Itsuki is the only one who holds onto a gut feeling that his friend will pull through, demonstrating a deep, almost instinctual bond with the series protagonist.