[It is - perhaps unsurprisingly - an unexpected and bold gesture to someone who doesn't even call people by their first name more often than not. Having expected something closer to a handshake, the surprise present is very much genuine.]

Simple indeed, but I wasn't aware that greetings outside of my country were so... ah, warm? [The polite way of saying "too familiar"... What is this. Society is complicated enough in ye olde Japan, who needs to deal with ye olde Not Actually England Or France and its ten thousand flatteries!!

Kaoru just looks vaguely flustered (and flattered accordingly) though, fingertips of the hand not in Vincent's resting against a cheek in a shy-looking gesture.]

But thank you for showing me, sir. Even though I've been here for some time, there is still much that's foreign to me... It's a little embarrassing.