SQ 631 and Haneda ANA Business Lounge
The last leg of my flight was actually a break up of my original booking. Although no stopovers are allowed for a one way award saver ticket, there is an unwritten rule where you can top up USD $100 for a stopover. Is the $100 worth it? Here is the math for it:
LAX-SIN is 88,000 miles (+ USD $37.63) via NRT
LAX-NRT is 85,000 miles (+ USD $23.60)
NRT-SIN is 43,000 miles (+ JPY 2610)
It is quite clear cut that for additional $100 USD, it will save you 40,000 miles (which is almost an additional J ticket from Singapore to Japan!)
The tough part however, is the availability of flight and getting the right person on the other side of the phone that is willing to do it for you. Don’t be disheartened if you get rejected on your first call (they may tell you that stopover is strictly not allowed on saver ticket). Keep trying!