Use of the terms of plain and thick type started with Tenka-ippin, when they referred to the chicken bone broth based white broth as the "thick type" and the chicken bone broth based clear broth as the "plain type" on their menu.
あっさり系、こってり系の呼称については、天下一品が自店の鶏ガラ白湯をこってり、鶏ガラ清湯をあっさりとメニューに記載したことから始まる。