| Age | 15 |
| Sex | Male |
| Car | Toyota Sprinter Trueno 2door GT-APEX (AE86) |
| Year | 1986 (Kouki) |
| Color | High-Tech Two-Tone |
| Voiced by | Atsushi Abe |
Shinji Inui (乾 信司 Inui Shinji) makes his debut during Project D's battle against Team Spiral. Shinji is a member of Sidewinder and therefore second driver of this team. Shinji appears to be a boy (possibly younger than Takumi) but seems very intelligent. Shinji's car is the notchback coupe variant of the AE86 Trueno (not to be confused with Takumi's Eight-Six). He is the fourth character to drive a Toyota AE86 model, after the fake Takumi's Trueno AE86. In the end of the final episode of 5th stage, it is unknown who won the race when he races Takumi's AE86. In the manga, Shinji lost to Takumi, due to both cars spinning out. With the tires of Takumi's 86 locking up, it sent Takumi's 86 into a spin. Shinji had no choice but to follow. At this moment, with the experience gained from the engine blow in Akagi when going against the Evo III, Takumi instinctively presses on the clutch, freeing up the tires and regained control of the 86 momentarily. However, Takumi is now going in reverse with inertia alone. Shinji, on the other hand, lacks actual dogfight experience and did not know what to do, spinning a full 360 degree, causing him to lose more momentum than Takumi did. Takumi won by crossing the finish line backwards with his 86. Shinji's 86 ended up facing the finish line after the 360 spin.
