| 1982 |
Kart Race Debut. Kansai Kart Land Series J Class Champion |
| 1983 |
All Japan A-1 Class National Champion (Kart) |
| 1985 |
All Japan A-1 Class West Champion (Kart) |
| 1986 |
All Japan A-2 Class Champion (Kart) |
| 1987 |
Formula Race Debut in FJ-1600. 4 Wins, 3 Pole Positions, 3 Lap Records. Rookie-of-the-Year Award. |
| 1988 |
All Japan F3 Championship. 2 podium finishes. International F3 Macau GP 1st leg: 8th 2nd leg: DNF |
| 1989 |
Formula Vauxhall Lotus Europe. 1 Win, 2 Pole Positions, 3 Lap Records. Ranking 5th. JMS Award |
| 1990 |
British F3 Championship Ranking 14th |
| 1991 |
British F3 Championship 1 Win Ranking 7th. Avon Fastest Lap Award. Became the first Japanese to win an single seater international race. |
| 1992 |
International F3000 Championship |
| 1993 |
International F3000 Championship, 2 wildcar entries in All Japan F3000 Championship. |
| 1994 |
International F3000 Championship First Japanese Driver to stand on the podium in the series. Formula 1 at Jerez, Suzuka, and Adelaide. |
| 1996 |
Indy Lights Championship First Japanese Driver to stand on the podium in the series. |
| 1997 |
Indy Lights Championship 1 Win. First Japanese Driver to become a winner in the series. |
| 1998 |
Formula Nippon 1 Podium, 1 Fastest Lap. All Japan GT Championship 1 Podium |
| 1999 |
Formula Nippon 1 Podium, 1 Pole Position, 2 Fastest Lap. All Japan GT Championship 1 Win, 1 Pole Position, 1 Fastest Lap |
| 2000 |
Formula Nippon 2 Podiums, 1 Fastest Lap. Ranking: 5th All Japan GT Championship Ranking 6th |
| 2001 |
Formula Nippon. All Japan GT Championship 2 Wins, 1 Podium |
| 2002 |
IRL IndyCar Series |
| 2003 |
Formula Nippon. Becomes Owner-Driver of Team MOHN |
| 2004 |
Formula Nippon |
| 2005 |
Formula Nippon. A1 Championship driver for Team Japan. |
| 2006 |
All Japan Sportcar Championship. Pole Position and Fastest Lap in all races. Ranking: 2nd. Le Mans Series entry in two races. |
| 2007 |
All Japan Sportcar Championship. 3 Wins. Series Champion |
| 2008 |
24 Heures Du Mans, Europe Le Mans Series, American Le Mans Series Wilcard in Laguna Seca |
| 2009 |
24 Heures Du Mans, Europe Le Mans Series, American Le Mans Series Wilcard in Laguna Seca and Road Atlanta, Asia Le Mans Series in Okayama and Suzuka |
