Going to study at a language school for 6 months. What are the best cities for this?

I'm planning to study Japanese at a language school (through GoGoNihon) for 6 months, starting in January 2027. Up until now I have really only looked into schools in Tokyo, since it is the place in Japan I know most about, it's the city with the most options for language schools and I think it would just be a very exciting city to explore in those 6 months. I was wondering if Tokyo really is the best place for me to stay during that period, or if there are any other cities that are just as exciting but more pleasant to live in for 6 months. By the way, I'm not planning to work while in Japan, if that is relevant at all.

Any recommendations for specific language schools that are available through GoGoNihon are also always welcome :D