Koichi Hiramoto

A hardworking man in the Green Auto Shop for 15 years who often races on the Wangan with his friend Harada until one day, the two encountered Reina's gray GT-R (white in the anime) which makes Hiramoto decide to get his own car, despite his promise to his pregnant wife Megumi that he had put his racing days behind him. When she learns of his decision, she leaves him to go live with her parents because it is better than wondering every night if he'll even come home. After extensive tuning of his GT-R, he challenges both the Devil Z and Blackbird. They run a long race, neck and neck the whole time. Hiramoto encounters one chance to pull ahead at the risk of his own life, but instead pulls back and drops out, realizing that there are more important things to live for. He then sells his car, giving up racing and returning to his wife who by then gave birth to their child.

(Source: Wikipedia)