All Nippon Airways Mileage Club - NH Upgrade Question

I am tying to figure out how I can get this to work. I fly once or twice a year to Osaka for business and I have to go again. Last time I lucked out on getting an op-up on the NH flight from HND-LAX (was in a fairly lowball coach fare, but an oversold flight and being *G probably helped) into C and I know I probably will not get it again but I was wondering if they allow a cash buy-up to their prem. eco? I am a bigger guy and their 16.5" seat width just is too narrow for me to be comfy on that long of a sector and I want to try and get at least a little sleep. I will say the NH flights out of HND are nice to be able to get a full work day in and then fly home but their Y seats are just not as spacious as other carriers...even EK/AF/KL have wider Y seats in a 10 abreast config vs. NH at 9 across.

1) There's no cash at the gate upgrades on NH.
2) If your ticket is changeable, you'd need to buy up to the PY applicable fare. at the airport, that's likely full Y or Full PY.

If your fare is mileage upgradable, that's another option.

The only way to get PY seats(for free) is to be an NH elite...

28 Dec I was offered an upgrade from coach to business class for $500 at check-in at LAX for NH5 LAX-NRT. The check-in agent specifically said they were offering that because coach was heavily oversold. I have no * alliance or NH status of any kind and it was a discounted economy fare.

28 Dec I was offered an upgrade from coach to business class for $500 at check-in at LAX for NH5 LAX-NRT. The check-in agent specifically said they were offering that because coach was heavily oversold. I have no * alliance or NH status of any kind and it was a discounted economy fare.

That is only because of the oversold situation, and normally other airlines would op up its own elites for free.

In general, they wouldn't ask or offer any paid upgrade to C class, they would rather choose to fly C class half empty.

Thanks to those who all replied, guess I will have to figure something out. Maybe fly into NRT and take the train to Osaka or try to use UA in and out of Osaka but for some reason it will not let me price out using UA in and out of KIX for some reason.