By the way, the term of a Derby match is originally used for indicating a match between teams whose hometowns are the same, but in Japan, is sometimes used also indicating a match that becomes especially excited due to a special historical reason, and the Kawanakajima Derby is a typical example of the latter type.
ちなみにダービーマッチとは本来、地元を同じくするチーム同士の試合をいうが、日本では因縁があったり特別盛り上がる試合を指すこともあり、川中島ダービーは後者。