Transit at Haneda for International flight

At the end of my trip, I will be flying from Okinawa to Singapore via Haneda (JAL + SQ) under 1 booking code. There are 2 hours between the flight. The domestic leg allows 20kg luggage while the international leg allows 30kg, so I'm planning use Ta-Q-bin to send some of my luggage from Okinawa to Haneda and pick it up during the transit time.

Will this arrangement work?

Why back Tokyo?
Guess cheaper via Hong Kong or.
Or send yr luggage to Singapore.

2 hrs transit possible or not is depends on need check-in or not.
http://www.haneda-airport.jp/inter/en/dept/dms_int.html
http://www.haneda-airport.jp/inter/en/dept/dep_step.html

You should check the luggage specifications with your booking airline. It has been my experience that if a domestic flight is booked on the same ticket as an international, you automatically get the international baggage allowance even on the domestic flight. But just in case it works differently depending on the airline, you should call and check that out for sure.

If you are going to T-Q-bin it, then I would allow at least 3 days for it to get to Haneda in time to pick it up before you check in.

Thank you for the replies.

@BR:
The returning flight is decided by my employer and it's the best option for the price. The other flight option is Asiana Airlines through Korea, which I don't favor due to lower baggage allowance.

@scarreddragon:
Maybe because your connecting flights are under one airline that the baggage policy follows the international allowance.

I have checked that the luggage from Okinawa will be carried thru until Singapore. However each airline's policy applied, which means JAL Okinawa-Haneda only have 20kg allowance. I'm not sure if additional checked baggage can be done in Haneda.

@John B digs Japan:
Thank you for the reminder. I am planning to send the luggage 3-5 days in advance. Do you have experience on how the good is the collection at Ta-Q-bin Haneda?

I only T-Q-bin between hotels and never the airport, as I have to re-pack things before my flight out.