Using HND suite lounge during an overnight layover
 

Arriving to HND in F at 8 pm, then I have a 12 hour layover before a J flight to HKG in the same terminal. Technically, can I go through international transit and show up at the suite lounge to get some food before they close at 1am? Would I then be stuck inside the terminal until morning?

official *A policy is no - lounge access is based on your departure flight status

ANA policy is yes, can access if you arrive F inbound and connecting "sameday". whether that applies to you, who knows?
https://www.flyertalk.com/forum/28719643-post65.html

if you are flying into HND, I would go into the city and stay overnight... food, explore, relax at an onsen/spa

Same day flight applies until the last flight of the evening departs around 1:30am and the lounge closes. So your departure will be considered a next day flight. I do suspect, though, that if you show up you would probably be let in.

You will basically be stuck in the terminal once the lounge closes. As you would need staff to assist you to get back to arrivals. At that time, public transport has also more or less shut down completely, exception for a few potential night busses. So you'd be stuck at the airport, or need to take a taxi somewhere.

There is an airside hotel, not cheap, but you could get a room there to catch some sleep after the lounge closes.

Why do you want to go to the lounge upon arrival?

Free food and drinks? But tbh, the standards of the Suite Lounge would not, IMHO, make that a very good use of time and effort.