I was charged a huge penalty for smoking cigarettes in a non-smoking room at a hotel.

Japan amended its Health Promotion Act that strengthened measures against passive smoking, which went into effect on April 1, 2020. Anti-passive smoking measures are in effect even at hotels. The amount of the fine charged by the hotel will be in its terms of agreement for staying at the hotel. Sometimes, the fine will be large because a room that has the odor of cigarettes cannot be used for some time or might require servicing. First ask for an explanation of the basis for the fine.