An upper of a shoe comprising: a first upper portion covering a lateral side of a toe; a second upper portion for providing a support covering a side surface of a ball of a little toe on a lateral-side surface; an overlap region α where the first upper portion and the second upper portion overlap each other on the lateral-side surface without constraining each other in a standstill position and a dorsiflexed state in which a foot is dorsiflexed; and a separation line at which the first upper portion and the second upper portion are separated from each other so that as the foot dorsiflexes from the standstill position, a front end of the second upper portion displaces with respect to the first upper portion so as to increase an area of the overlap region α, wherein a position of a lower end of the separation line in a front-rear direction of the foot is set to be anterior to a metatarsal phalangeal joint of the little toe and posterior to a tip of a fourth toe, wherein the separation line extends downwardly from an upper edge of the first upper portion to the lower end, and the separation line is continuous with an opening anterior to a wearing opening of the upper and extends from the opening to the lower end toward the lateral side of the foot; characterized in that the upper further comprises a lateral-side continuous portion, extending from the lower end of the separation line to an upper end of soles (Sm and So) of a shoe, the first upper portion and the second upper portion being continuous with each other in the front-rear direction of the foot more firmly in the lateral-side continuous portion than in the overlap region α; and the lateral-side continuous portion is formed by the first upper portion and the second upper portion connected to each other. a first upper portion covering a lateral side of a toe; a second upper portion for providing a support covering a side surface of a ball of a little toe on a lateral-side surface; an overlap region α where the first upper portion and the second upper portion overlap each other on the lateral-side surface without constraining each other in a standstill position and a dorsiflexed state in which a foot is dorsiflexed; and a separation line at which the first upper portion and the second upper portion are separated from each other so that as the foot dorsiflexes from the standstill position, a front end of the second upper portion displaces with respect to the first upper portion so as to increase an area of the overlap region α, wherein a position of a lower end of the separation line in a front-rear direction of the foot is set to be anterior to a metatarsal phalangeal joint of the little toe and posterior to a tip of a fourth toe, wherein the separation line extends downwardly from an upper edge of the first upper portion to the lower end, and the separation line is continuous with an opening anterior to a wearing opening of the upper and extends from the opening to the lower end toward the lateral side of the foot; characterized in that the upper further comprises a lateral-side continuous portion, extending from the lower end of the separation line to an upper end of soles (Sm and So) of a shoe, the first upper portion and the second upper portion being continuous with each other in the front-rear direction of the foot more firmly in the lateral-side continuous portion than in the overlap region α; and the lateral-side continuous portion is formed by the first upper portion and the second upper portion connected to each other.