https://en.wikipedia.org/wiki/Electricity_sector_in_Japan
EDIT: these numbers appear to be old, since 2019 they’ve tuned reactors back on and stopped relying on LNG as much. I can’t find good numbers on recent data but in 2019 they imported more gas than any other country.
Source: https://www.isep.or.jp/en/1243/
Reference #4
Renewables are aggressively scaling up and nuclear looks like it's rebounding some.