The Debonair was Mitsubishi's competitor to the Nissan Cedric, Prince Gloria, Isuzu Bellel, and Toyota Crown and during the first-generation's production, the appearance remained generally unchanged from 1964 until 1986, sharing a tradition with the Toyota Century, that being iconically recognized as a senior executive sedan exclusive to the Japanese domestic market. Although it received several minor redesigns (denoted I through IV), the vehicle proved popular enough in the Japanese executive market to remain in production for 22 years without major appearance modifications.