Image from McDonald's Japan.
At $4.00 a bottle, I was reluctant to simply dump it down the drain, so I tried to figure out other ways to consume it. The thing that worked was adding it to coffee. This didn't exactly make the coffee better, but it didn't really make it any worse. The coffee was strong enough that there was just a hint of coconut riding on the edge of the bitter waves. I'm down to about 1/6 of the bottle and wouldn't buy it again, but can't say that I hated using it as I have.
I think that coffee is a pretty forgiving beverage, but I would never really think about adding orange to it. In fact, citrus and coffee of any sort would seem to be a bad combination considering that one seems to alter the taste buds in a way that make the other taste funky in my experience. To each their own, but I wouldn't be trying to off-load my orange Torani in coffee (especially because the orange tasted fine mixed with water or my husband's drinks).
In addition to the orange latte, McCafe (which is the coffee arm of McDonald's) is offering something called a "babychino". As a way of introducing infants into coffee culture, they are selling steamed milk with sweet cocoa powder. The "babychino" is a mere 50 yen (about 50 cents), which is probably their way of pricing it as a "gateway drug". Later, they'll be able to hit the grown baby up for various coffee beverages in the $2.50-$3.50 (230-350 yen) range.