First of all, the word tsundere was first introduced in 2002... This was the internet term, but its original definition was, "Someone who is tsuntsun at first, then later becomes deredere."
そもそもツンデレという 語が 誕生した2002 年、ネット 上でのことでしたが、その 際 掲げられた 定義とは、 最初はツンツン、やがてデレデレ