it does mean toyota in japanese......
and if you look close you will find it on just about every part of your car that is the original part from inside the head to under the manifold even on some gas caps, oil caps, and on the valves. it is just a short way of branding it was there before the old skool T (like you see on the 60's-early 80's rims) or the new and improved "T" (aka the toyota symbol)