Mount Fuji is about  southwest of Tokyo. There is a low risk of eruption. The last recorded was the Hōei eruption which started on December 16, 1707, and ended about January 1, 1708 (16 days). During the Hōei eruption, the ash amount was 4 cm in southern Tokyo (bay area) and 2 cm to 0.5 cm in central Tokyo. Kanagawa had 16 cm to 8 cm ash and Saitama 0.5 to 0 cm. If the wind blows north-east it could send volcanic ash to Tokyo metropolis. According to the government, less than a millimeter of the volcanic ash from a Mt. Fuji eruption could cause power grid problems such as blackouts and stop trains in the Tokyo metropolitan area. A mixture of ash with rain could stick to cellphone antennas, power lines and cause temporary power outages. The affected areas would need to be evacuated.