Places to practice saxophone outside in Tokyo

Hi all,

I will soon spend a few weeks in Tokyo and am looking for places to practice my soprano saxophone.

I have heard that Karaoke places are good, but i

I am also looking for places to practice outside. Do you know river banks or parks, where it would be ok to play?

Do you also have good recommendations of jam sessions for middle level jazz player (around 40 standards)?

Thanks a lot!