In the "Kagaku-shu" (a Japanese dictionary made in the Muromachi period) written in 1444, the origin of the name of torinoko (literary, a child of a hen) was described as 'The color of paper looks like that of an egg of a hen, so it was called torinoko.'
鳥の子の名の由来については、文安元年（1444年）成立の『下学集』では、「紙の色　鳥の卵の如し　故に鳥の子というなり」と説明している。