Bizarre, Shakespeare-spouting buffoon of Ranma 1/2 fame. He is the apparent head of the House of Kunou as his father is a ridiculous hippy who can be seen only wearing a Hawaiian shirt and sunglasses. A good indicator of Kunou's bizarre stock is that his father is also the school principal. Kunou is best known for being utterly oblivious as to the curse of Ranma Saotome.
For those unfamiliar with the series, Ranma turns from male to female when splashed with cold water and returns to his original gender (male) when splashed with warm water. This is the result of a curse incurred by falling into one of the cursed springs at Jusenkyo.
Ranma's curse is the primary source of weird situations involving Kunou, as Kunou is in love with the female Ranma (whom he knows only as "the pig-tailed girl") and has sworn mortal vengeance against the male Ranma. Kunou constantly looks like an ass as a result of his Lois Lane-esque stupidity in recognizing Ranma's curse-- male and female Ranma look almost exactly the same barring height, hair color, and certain anatomical details.
Kunou likes to call himself "the blue thunder." He is reasonably skilled at Kendo, the Japanese art of fencing, and would be quite dangerous if he weren't a complete dolt. He is also in love with Ranma's fiancée, Akane Tendo, and believes her to be his "destiny." His sister, Kodachi ("the black rose"), is his opposite, in love with male Ranma and mortal enemy to both female Ranma and Akane.
As an interesting aside, Kunou's first name, Tatewaki means "bring a sword."