| 1956 |
Awarded the 34th Akutagawa Prize for his novel, Taiyo no Kisetsu (Season of the Sun) |
| 1968 |
Elected to the House of Councillors (Upper House) for the first time |
| 1972 |
Elected to the House of Representatives (Lower House) for
the first time (elected eight consecutive times) |
| 1976 |
Appointed Minister of State, Director-General of Environment Agency,Fukuda Cabinet |
| 1987 |
Appointed Minister of Transport, Takeshita Cabinet |
| 1989 |
Ran in Liberal Democratic Party presidential election |
| 1995 |
Resigned from the Diet |
| 1999 |
Elected Governor of Tokyo (first term) |
| 2003 |
Re-elected Governor of Tokyo (second term) |
| 2007 |
Re-elected Governor of Tokyo (third term) |
| 2011 |
Re-elected Governor of Tokyo (fourth term) |