It is said to have been originated by Shigeru CHIBA, who played for a team of the Nippon Professional Baseball called Yomiuri Giants and was a regular customer at "Grill Swiss", a western-style restaurant in Ginza 3-chome in Tokyo; he used to order tonkatsu and curry and rice separately, however one day asked: "Bring curry and rice with tonkatsu placed on top."
起源は、東京の銀座三丁目にある洋食店「グリルスイス」にて、常連客で当時日本プロ野球機構・読売ジャイアンツの選手であった千葉茂が食事をした際、それまではとんかつとカレーライスを別々に頼んでいたが、ある時、『とんかつをカレーライスの上に乗せて持って来てくれ』と注文した。