Honda/Acura MTF I (just called "MTF") is a 30W conventional oil with a Honda additive package.
Honda/Acura MTF II ("white cap") is an ATF-based <20W fluid with Honda friction modifiers. It pours like water.
Honda/Acura MTF III (Euro only) is a semi-synth 30W oil with a Honda additive package.
All are made by Idemitsu for Honda.
MTF I is long discontinued (20+ years) but maybe there is some new old stock out there. MTF II was developed because customers complained about notchy cold shifting in the newer models of Civic and Accord. Honda went to the MTF III in Europe for unknown reasons (maybe environmental regs?), but kept the MTF II in US/Canada. It's still the dealer stock here. From the looks of your bottle, that was Acura MTF I. Given how few MT Hondas/Acuras are out there these days, I wouldn't be surprised if dealers had some of the old stuff still on the shelf.
It's totally fine to use in your NSX. Both MTF I and II are certified by Honda for the 5-speed and 6-speed NSX transmissions. I don't know if Honda approved MTF III for the NSX in Europe, but maybe some of our Euro members can chime in. Even a 5W-30 or 10W-30 motor oil is ok too- all early NSXs left the factory with motor oil in the transmissions. As long as it's no thicker than 30W, it'll be ok for your trans.
I know you already drained it, but posting here for future members who may find this thread.