The most underrated areas of Tokyo/Japan from January to April

Hello!

I'm going to Japan from 21st Jan to 21st April (ill also be in South Korea from Mid February to Mid March in-between). I've built up a lot of research, specifically in Tokyo as I know people say that it's almost impossible to explore every part of that city and I'm finding it quite overwhelming at the moment. I wanted to ask the more avid Japan travellers here; are there any parts of Tokyo that you believe are underrated and deserve more exploration? Or even, are there any areas of Japan that are ideal during those months that don't involve skiing etc? Any advice would be greatly appreciated x

by Single-Poet230