Kazuki is the son of Satoru Nakajima, who between 1987 and 1991 contested 74 Grands Prix with Lotus and Tyrrell.
Under the guidance of his father, Kazuki began Karting in his early teens, gradually making his mark and winning the Suzuka Formula ICA Karting Championship.
In 2002, aged 17, he won a scholarship with the Formula Toyota Racing School, going on to win the Formula Toyota Championship a year later.
By now a part of Toyota's Young Drivers Program, Kazuki moved up to the Japanese F3 Championship in 2004, finishing fifth overall. He remained in the series in 2005, this time finishing runner-up, in addition to taking part in a number of Super GT GT300 events.
In 2006, Kazuki moved to Europe, contesting the Formula 3 Euroseries, in which he came up against the likes of Sebastian Vettel and Paul di Resta. The Japanese youngster finished seventh overall, but capped his year by being named as Williams second test driver for 2007, the British team having secured a deal to use Toyota engines.
Kazuki took part in a number of tests at the end of 2006 and the beginning of 2007, giving a fairly good account of himself as he familiarised himself with the team and the FW29
In addition to his duties with Williams, he also contested the GP2 Series, partnering Nicolas Lapierre at DAMS. Though there were no wins, there were a number of strong performances, most notably at Silverstone, the Nurburgring and at the Hungaroring where he finished second in Race 1. By season end, he was fifth in the Drivers' Championship, his 44 points going some way to helping DAMS secure fifth in the Teams' Championship.
When Alex Wurz made the shock announcement that he was quitting F1 as a race driver - with immediate effect - ahead of the season finale, there was no choice for Williams but to give Kazuki his F1 debut.
Other than a botched pit stop, which saw the youngster knock down one of his crew, it was a strong performance, the Japanese driver bringing the car home in tenth. However, fifth fastest lap of the race, ahead of his own teammate, indicated that the youngster has raw pace.
No doubt with a little assistance from Toyota, Kazuki was given a full race seat alongside Nico Rosberg in 2009, giving the Grove outfit one of the most inexperienced driver partnerships on the grid.
Over the course of the season, Kazuki gave a fairly good account of himself. While he was out-qualified by his German teammate 14 times, the Japanese youngster was closer to Rosberg's race pace.
The season got off to a dream start with 6th in Melbourne, admittedly partly thanks to the disqualification of Rubens Barrichello, while another 2 points were picked up in Spain, where he out-qualified his teammate.
In Monaco, Kazuki made a little bit of F1 history, becoming the first Japanese driver to finish in the points in the Principality, scoring further points in Britain and Singapore.
Sadly, there were mistakes along the way, most notably Turkey where he collided with Fisichella. Then there was Canada where he hit the pit wall whilst stopping for a new front wing.
On the whole however, and considering the equipment at his disposal, it was an OK rookie season, though were all hoping for an improvement in 2009, Rosberg being the ideal benchmark.
Sadly it was not to be. While the FW31 was pretty much bullet-proof, completing 92% of all racing laps over the course of the season, Kazuki didn't score a single point.
While he was much closer to Rosberg than in 2008, out-qualifying the German three times, the tightness of the field, a general lack of fight and a few needless mistakes meant the likeable Japanese driver failed to make an impression.
Following a crash in Melbourne Kazuki suffered the ignominy of being the only retirement in Bahrain, his oil pressure failing just five laps from the end.
He crashed again in Monaco while a certain points finish in Turkey was lost due to a problem with the cover on his left-front wheel, prior to the stop the Japanese driver had run as high as fourth.
At Silverstone, Kazuki produced his best ever qualifying result putting his Williams fifth on the grid. However, poor pit-stop strategy meant the youngster finished well outside the points.
In Hungary, having made it through to Q3 for the third time, Kazuki finished ninth just 0.7s behind the last of the point scorers Jarno Trulli.
Having finished ninth again in Singapore, Kazuki suffered further bad luck in Brazil when he was hit by countryman and newcomer Kamui Kobayashi, the Williams driver once again cruelly robbed of a certain points finish.
With Rubens Barrichello and Nico Hulkenberg confirmed for 2010 and Toyota leaving the sport, it looks very much as though Kazuki's F1 career is over, at least for now.
Over the off-season he hasn't been linked with any of the available F1 drives while to add to his frustration Kobayashi - who was never particularly impressive prior to F1 but was quite sensational when he did arrive - has secured a seat with Sauber.
There's no mistaking the fact that Kazuki does have talent, furthermore he's a very nice guy, however, given two seasons in which to prove himself he clearly hasn't done so, certainly not to the satisfaction of those that matter most the team bosses.
Statistics - at the end of 2009 Season
Drivers' Titles: 0
Seasons in F1: 2
Grand Prix: 35
Fastest Laps: 0
Best result in 2009: 9th (2 times)
Best qualifying 2009: 5th (Britain)
Worst qualifying 2009: 18th (Belgium)
2009: Out-qualified Nico Rosberg 3 times
2008: Out-qualified by Nico Rosberg 14 times
2009: Completed 878 out of 988 laps (88.9%)
2009: Finished 13 times from 17 starts (76%)