Upgrade to first from business D class?

[RTW4]

Does anyone know if I can upgrade with miles or cash from D to either A or F class on a LAX-NRT flight? Thanks

[SQflyergirl]

with miles yes - but you book into O class, not F or A.

With cash - depends on your fare basis, but you could definitely buy full fare if you wanted to

[TerryK]

You can book into A class if you use double SQ miles.