Very cool but if someone tells you they’re uncomfortable with you flaunting a weapon in front of them you should just stop instead of committing to the bit
Took me a bit of digging, but the song here is part of the Bushido Blade OST, it's called "Those who aim at the castle tower" the bit here is only at certain parts of the song, like a minute and thirty in or so and close to the end. Like this so it stays closer to the top, just so that others can see it more easily.
He has Filipino in his blood. They invented the balisong aka butterfly knife. Asking them for a knife fight is like challenging an arms dealer to a shootout.