I was working in the construction of "第二東名高速道路" (Daini-Tomei Expressway) at Shizuoka city, province of Shizuoka, Japan.While I was leaving Shizuoka city, in the direction of Fujieda (my based hometown), I saw in the sky, something like a star, it was very strange, because at 17:00 I have never saw anything like that in the sky! Ok, I took the Rote 1 (by-pass), and that strange object still was in the sky. I went the whole way in the by-pass looking into the sky and that bright object, when I leaved one of many tunnels in this by-pass, "we" (me and my colleague) saw a black UFO !!!Sorry, my English is not good, but I will try to explain how it looks like...It was about 6 meter length, by 1.5 meter height, totally black and disc as shape.I could observe that it wasn't a perfect "circle/disc" shape, as it had 4 faced very slighty .I will use these videos to relate it formats: http://www.youtube.com/watch?v=KjY0cmp1QiI (it appears at 06:32)and with a mix of this http://www.youtube.com/watch?v=nywEAj2C8eoNow imagine this solar ballon bigger (6 meter length by 1.5 meter height), and its corner more roundish, almost forming a circle disc.This object was floating about 15 meter above the ground, and 20 meters away the by-pass. In a place without access!I know what is a solar balloon, and that definitively was not the case!!!Its shape haven't any signal of seam, screw/bolt, door, window, engine (no sound), and doens't look that transparent plastic as solar ballon is.That UFO was more like black metallic very polish bright !!!NOTES:When I got in my "real home" (here in Okazaki-shi, province of Aichi-ken) in the next weekend, I could checked on STELLARIUM [http://www.stellarium.org/] that, in that day and that hour and place, there was not to be any star or planet!!!The first object was visible the whole time, and that black UFO for about 40 secounds.