Hi I have the same situation with a 445am arrival into HND with an onward flight much much later that day. (night). Can one enter airside and use lounges and leave a bag and then go into the city for 12 hours? I was planning on doing this but as I travel more internationally I am learning that not all the airports are like in the US where you can just come and go as much as you want.

I was hoping to shower at JL F, have breakfast then go for French toast at CX and then head into the city w/ leaving my carry on bag at the JL F lounge.

Thanks