Places in Tokyo/Osaka without much tourist crowds

Hello redditors! I’m planning a trip with my family (2 minors 14-17 and 2 adults) on 27th of April- 11th of May I am mostly planning this trip myself, and ofc I’m using most popular random websites to search for attractions and what to do in Osaka and Tokyo (also might be going to Kyoto)

My mom started hesitating about this trip because she’s getting stressed that there will be too many people everywhere (Might sound kinda strange but I can get her), so I wanted to ask if any of you would’ve liked to share some hidden gems- nice locations in these cities which are not that much crowded as some popular attractions are but we’re still interesting for you/you find them underrated. Or maybe I just gotta look for these on spot when we arrive in there???

Mostly talking about parks/ just some places to relax(any kind of spas are also welcomed!) and restaurants ( probably above mid prices )

I really hope I managed to formulate my questions correctly, thanks! 🦆