And both leads are into it. Perhaps because they're both too busy with their careers so they're fine marrying just about anyone to please the family and save time from the whole dating charade and whatever.

So no fake marriage, or marriage in name only, or contractual marriage... but the real deal, but it happens over a night, yet both leads have no emotions invested in it.

Shanai Marriage Honey ...?  I wouldn't say "both too busy with careers", though.