For example,
on 20Dec(SUN)
JL901 HNDOKA(J) 2072FOP 17920JPY
JTA557 OKAMMY(J) 700FOP 8900JPY
JTA558 MMYOKA(J) 700FOP 10900JPY
JTA565 OKAMMY(J) 700FOP 8500JPY
JTA564 MMYOKA(J) 700FOP 8900JPY
JL920 OKAHND(J) 2072FOP 22790JPY
Or, if you are scheduling TPE run, you can add a domestic sector with 5940JPY (two sectors for inbound and outbound).
See
http://www.jal.co.jp/en/inter/fare/dom.html (in English)
So,
OKA-HND-TPE-HND costs 5940JPY more than HND-TPE-HND.
And this OKA-HND earns 2368FOP.
Of course, you have to buy a separate HND-OKA ticket for a positioning flight.