The following season allowed him the chance to discover the new venues alongside new 125 champion Dani Pedrosa, and he finished sixth overall in a solid season in which he scored two podiums.
He continued with the same team in 2005, picking up his first Grand Prix victory at his home round at Motegi, completing another impressive season in fourth spot in the championship.
Moving to the KTM team for 2006, he was in the running for third place in the championship before a crash in the final round at Valencia. The Japanese rider had repeated his home victory, whilst his win in Turkey in the third Grand Prix of that year was also KTMs first ever victory in the quarter-litre class.
After two more victories and four podium finishes in 2007 he continued alongside Mika Kallio on the solid KTM package in 2008, ending up a somewhat disappointing seventh overall having secured just two podiums with second places in China and Malaysia. With the withdrawal of the Austrian factory from 250 his future plans were shrouded in doubt for 2009, but the Scot Racing Team picked up the popular rider after his compatriot Yuki Takahashi moved up to represent the team in the premier class.
It proved to be an inspired choice as on his return to the Honda ranks Aoyama consistently scored impressive results including four wins and a further three podiums. He scored points at every single race, and only finished outside of the top four on five occasions, figures which many believed impossible on a bike which had not won a title at this level since 2005.
Aoyama will move up to MotoGP with a Honda in 2010 crowned as the new 250cc World Champion, having secured the title in dramatic fashion at the final round in Valencia when just an eleventh place finish was needed. He ran off track and almost crashed at one stage, but eventually brought his bike home in seventh place whilst title rival Marco Simoncelli crashed out of the race lead.
Date of birth: 25/10/1981 (28 years)
Place of birth: Chiba (Japan)
Some facts about Aoyamas achievement
Aoyama is the third Japanese rider to win the 250cc world title joining Tetsuya Harada in 1993 and Daijiro Kato in 2001.
He is the first Honda rider to win a world championship in any class since Nicky Hayden took the MotoGP title in 2006.
He is the first Japanese rider to win a world title in any class since Daijiro Kato took the 250cc championship in 2001.
Aoyama finished in the top eight at every race in 2009.
He has not missed starting a Grand Prix since making his debut as a full-time GP rider at the first race of 2004.
At the San Marino Grand Prix this year Aoyama became the first Japanese rider to pass the milestone of 100 Grand Prix starts in the 250cc class.
Career Data in 250cc
First Grand Prix: PAC 2000
First Pole Position: JPN 2003
First Podium: PAC 2000
First GP Victory: JPN 2003
Grand Prix Starts: 104
Grand Prix Victories: 9
Pole Positions: 8
Race Fastest Laps: 11
World Championship Wins: 1 250cc 2009