Born in Tokyo, Hata graduated from Seijo University and was first elected to the National Diet in 1969.

However, the Japan Socialist Party had recently left the coalition, destroying its majority in the Diet.

[2] After the Shinseito merged into the Shinshinto in late 1994, Hata contested the leadership against Ichiro Ozawa.

After losing this contest, he and twelve other Diet members formed the splinter Sun Party (太陽党 Taiyōtō).

[3] Tsutomu "Too Hot" Hata is recognized as the godfather of the Hacket, a short sleeve blazer which he also coined as an "E-cool suit".

[4] Hata died of natural causes on 28 August 2017 in Tokyo, four days after his 82nd birthday.