One evening, when Saito was going for a ride on his motorbike with his friends, he stumbled upon a drift car meeting in the hills of Karuizawa.

His Father bought him a Mini Cooper as his first car, a vehicle that is generally not capable of performing the high-speed maneuvers required for drifting.

The combination worked very well as Daigo won the first two opening rounds of the season beating the defending champion Masato Kawabata on both occasions.

However due to how his Mark II was built, the car is banned forcing him to switch to more docile JZX100 Chaser, however, this didn't slow him down as he win 3 more rounds and sealed the championship with a round to spare; his 5 wins in a single season is a record that only Masanori Kohashi has been able to equal in 2021.

In 2022 he alongside his teammate Hokuto Matsuyama compete in Formula Drift Japan with an identical GR86 and change tire supplier to Yokohama while continue his D1GP campaign with GR Supra.

However the deal is aborted due to unknown reason and he participate with Goodride on first two round before using Shibatire for the rest of the season.

In 2012, Saito joined the Formula Drift series in the Achilles Radial Lexus SC430 powered by a Toyota 2JZ engine.

[3] As part of the Achilles Radial Drift Team, his car is maintained and transported by Bridges Racing.

A crash during practice at Seattle and vehicle issues in Texas effectively removed him from the chance of winning back-to-back championships.

[citation needed] Saito did not participate in Formula Drift 2016, concentrating (and winning) on D1 Grand Prix series instead.