A samurai, duelist, and master swordsman that lived in Japan in the 1600s under the reign of Tokugawa Ieyasu. He was a remarkable fighter, having won 60 duels, and invented the two sword style of using a katana and a wakizashi at the same time. He was called a kensei, or sword saint, and is a famous person in Japanese history. More importantly, he was a fine artist and writer, and is the author of "The Book of Five Rings", which is a fascinating text on martial sciences and strategy.
When the mens room at your office building has not been cleaned for an amount of time that allows the rim of the urinal to collect pubic hair. The collection then appears like a mustache on the rim.
I almost puked when I had to use the restroom and the urinal mustache tickled my hand.