To "buy" some ANA miles without leaving the house, Starwood is an option:
With SPG, as a Platinum member you can convert 1 mile only to ANA 1:1. For Gold members there's a minimum of 1500 miles, for non-status preferred members it's minimum 2500 miles.
500 miles cost 17.50 $, maximum cost without SPG status 5* 17.50 $ = 87.50 $, with status less.
Hilton: 100 $ for 10000 points = 1000 ANA miles.
Marriott: 125 $ for 10000 points = 1500 ANA miles
ICH Priority Club: 125 $ for 10000 points = 2000 ANA miles