This guy got denied entry to the lounge upon arrival as his connecting flights wasn't until the following day.
https://liveandletsfly.com/tokyo-haneda-transit/
Rules are the rules but seems crappy not to allow arriving transit passengers into the lounge.
I'm considering the same flight with the 15 hour layover.
I have Priority Pass as well. Do I need a same-day ticket to access with Priority Pass as well?