If you stay in Kowloon (and I would also recommend the HR...last chance to get a FFN...relatively cheap, given that it's closing down at the end of the year), you might want to consider going to the night market.

There is massive construction work going on at the peak just now although it is probably still worth going up just for the tram journey.

I think staying at the airport hotel is a good idea as that would mean you'd get straight to bed off the plane (coming from Japan you gain a couple of hours so it will feel later) and then you could get up nice and early the following morning, onto the airport express into town (only 22 minutes and leaves every 12) and you could do Serfty's itinerary which I think is bang on.

One other thing is on the Kowloon side of the Star Ferry you could have a wander along the Avenue of Stars and search out Jackie Chan's hand prints - it's a little bit tacky but you are on the harbour front and you get great views of Hong Kong's skyline.

Enjoy!