11 hour stopover in Narita - Luggage?

I'm going to have about an 11 hour transit at Narita where I will arrive from Singapore to Japan at 08:00 and the connecting flight to Los Angeles will be at 19:15 which will also depart from Narita.

Since it's roughly half a day (not counting the time it takes to get in/out of the airport), I was hoping to leave the airport and go into Tokyo to meet up with some friends. However, I'm wondering about my luggage: will it automatically be checked through to the final destination? Or will I need to pick it up and either check it in again/put it into storage?

I'm flying with Singapore Air for all of my flights, and this will be my first time trying to leave the airport during a layover. If any of you have any experience or advice, please let me know. Thank you!

The airline will hold your luggage for you and it will be placed onto your departing flight the next day as normal. If you wish to retrieve your bag(s), you can, and then re-check them the next day.