Why did the Japan GP switch from Suzuka to Fuji?

Answer 1

The contract with Suzuka expires at the end of this season and Fuji, a Toyota track, has been refurbished and obviously offered Bernard Charles Ecclestone a better deal.
The Mt Fuji circuit was the original home of the Japanese Grand Prix, having hosted the race in 1976 and 1977.
The 1976 race was won by Mario Andretti in a Lotus Ford and in 1977 by James Hunt in a McLaren-Ford. Two spectators were killed at that race following an accident between Gilles Villeneuve and Ronnie Peterson.