You do a majority of freight, so overnights are not quite what you might euphemistically describe as "overnights". That being the case, taxi to HND, fly to OKA, then PVG, arrive in the morning, that night it's back the other way, with the only difference you catch a bus back to NRT instead of a taxi is not a popular one.
On the PAX side you can get 9 hours or less in TPE, CAN AND HKG, but it is during the night!