Like most drivers, Kobayashi initially made a name for himself racing in local and then national karting tournaments in his home country. Aged just nine, the Japanese youngster finished third in the SL Takarazuka Tournament Cadet Class and over the next seven years clinched a further five junior titles. By then hed done enough to catch the much sought-after attentions of Toyota and in 2001 landed a place in the Japanese manufacturers young drivers programme.
This led to his first full season of single-seaters in 2003, when he finished second overall in Formula Toyota. Continued financial support from Toyota saw him head to Europe in 2004, where he chose the Italian Formula Renault series to launch his international racing career. It was a brave move but Kobayashi proved up to the task, with two wins and three pole positions taking him to seventh in the final standings.
Keen for any opportunity to race, he also competed in rounds of the 2004 Dutch and German Formula Renault series, as well as the Formula Renault Asia Challenge. Clearly not afraid of hard work, Kobayashi chose to stick with Formula Renault for 2005, this time entering the Italian and Euro series. With six wins and four pole positions in each, he took both championships with ease.
From there he followed the well-trodden path into Formula Three. Racing in the 2006 F3 Euro series he scored three podiums in his first season and finished the year eighth overall. Another outing at the prestigious Macau Grand Prix saw him take a surprise pole, an impressive achievement despite only finishing the race 19th.
Kobayashi had impressed enough for Toyota to offer him his first taste of a Formula One car with three days of testing during the winter break, before returning to his day job to compete in a second season of Formula Three Euro in 2007.
His second attempt at the series proved more promising than his first and he drove to fourth in the standings after a win and a further six podiums. Although team mate and future Renault Formula One driver Romain Grosjean took the title, with his raw speed and a growing maturity behind the wheel, Toyota had more than enough reason to offer Kobayashi a fuller F1 role and signed him up as their third driver for the 2008 season.
Wanting to keep his hand in with racing, however, Kobayashi also joined the super-competitive GP2 Asia and main GP2 Series. He enjoyed two wins in the Asian competition to finish sixth overall, before scoring a maiden main series win in the Catalunya sprint race. He went on to finish 16th in the table, a worthy performance for a debutant.
Despite competing in 30 races that season there was no let up for Kobayashi during the winter break, with the 2009 GP2 Asia series getting underway in October 08. Driving for the DAMS team he scored two wins on his way to claiming the title, though he was unable to carry that success into the main GP2 Series that got underway in May 09 and again finished 16th with one podium. 2009 also saw Kobayashi continue his third driver and testing duties for Toyota. He was one of the few testers to enjoy track time in an 09 car, covering four days (and 165 laps) over the winter.
That meant that when Timo Glock succumbed to a heavy cold and fever ahead of Octobers Japanese Grand Prix, Toyota didnt hesitate in drafting Kobayashi in for the Friday practice sessions. Despite just a few hours notice, he acquitted himself well, coping with Suzukas wet conditions with a confidence that belied his inexperience. Although Glock returned on the Saturday, a qualifying accident ruled the German out of the race. Sadly, however, Kobayashi was not allowed to compete in his place, having not practised on Saturday as required by the regulations
Then, just as it looked as though hed missed his big chance, news that Glock had a cracked vertebra in his back meant Kobayashi was called up again for the seasons final two rounds in Brazil and Abu Dhabi. He narrowly missed out on a point on his Sao Paulo debut, finishing ninth, before an aggressive drive took him to sixth place at Yas Marina. Toyotas subsequent F1 withdrawal came as a blow, but Kobayashi instead signed to race full-time for BMW Sauber in 2010.
Over the following two seasons with the Swiss team, he established himself as one of the most aggressive and entertaining racers on the grid. In 2010 he put two experienced team mates (Pedro de la Rosa and Nick Heidfeld) firmly in the shade as he scored 32 of Saubers 44 points, en route to 12th in the driver standings. He achieved the same placing in 2011, his best result a spectacular fifth place in Monaco, and was retained by the team for 2012.