A shoe having an upper and a sole, the shoe comprising: a flexible member forming a part of the upper and adapted to cover a medial side surface of a foot; and first and second reinforcement portions and being less stretchable than the flexible member and attached to a surface of the flexible member, characterized in that the flexible member includes a reinforced area reinforced by the first and the second reinforcement portions and; at least a surface member of the flexible member in the area includes a mesh fabric capable of stretching and shrinking in an up-down direction and in a front-rear direction of the shoe; the first reinforcement portion continuously extends, in a band-shaped form or a linear-shaped form, upward from a boundary portion of the upper with respect to the sole; the second reinforcement portion is placed posterior to the first reinforcement portion and continuously extends, in a band-shaped form or a linear-shaped form, upward from the boundary portion of the upper with respect to the sole; the area is defined by a first envelope line along a posterior edge of the first reinforcement portion and a second envelope line along an anterior edge of the second reinforcement portion; the area extends along a virtual first center line, which divides the area into a first portion whose anterior edge is defined by the first envelope line and a second portion whose posterior edge is defined by the second envelope line; the area includes an upper end portion, a lower end portion, and an intermediate portion between the upper end portion and the lower end portion; a width of the area in a direction perpendicular to a direction along which the first center line extends is at maximum in the intermediate portion, the width of the area gradually decreasing toward the upper end portion from the intermediate portion, and the width of the area gradually decreasing toward the lower end portion from the intermediate portion; a length of the area in the direction along which the virtual first center line extends is greater than the maximum value of the width of the area; the two reinforcement portions and form a casing shape; the reinforcement portions and has such an anisotropy that they stretch less easily in the direction along the first center line while stretching more easily in the direction perpendicular to the direction; the upper end portion of the area is placed anterior to the lower end portion of the area; and respective upper ends and of the first and the second reinforcement portions and are continuous with an engagement portion with which a shoelace engages, and respective lower ends and of the first and the second reinforcement portions and are continuous with an upper surface of the sole. a flexible member forming a part of the upper and adapted to cover a medial side surface of a foot; and first and second reinforcement portions and being less stretchable than the flexible member and attached to a surface of the flexible member, characterized in that the flexible member includes a reinforced area reinforced by the first and the second reinforcement portions and; at least a surface member of the flexible member in the area includes a mesh fabric capable of stretching and shrinking in an up-down direction and in a front-rear direction of the shoe; the first reinforcement portion continuously extends, in a band-shaped form or a linear-shaped form, upward from a boundary portion of the upper with respect to the sole; the second reinforcement portion is placed posterior to the first reinforcement portion and continuously extends, in a band-shaped form or a linear-shaped form, upward from the boundary portion of the upper with respect to the sole; the area is defined by a first envelope line along a posterior edge of the first reinforcement portion and a second envelope line along an anterior edge of the second reinforcement portion; the area extends along a virtual first center line, which divides the area into a first portion whose anterior edge is defined by the first envelope line and a second portion whose posterior edge is defined by the second envelope line; the area includes an upper end portion, a lower end portion, and an intermediate portion between the upper end portion and the lower end portion; a width of the area in a direction perpendicular to a direction along which the first center line extends is at maximum in the intermediate portion, the width of the area gradually decreasing toward the upper end portion from the intermediate portion, and the width of the area gradually decreasing toward the lower end portion from the intermediate portion; a length of the area in the direction along which the virtual first center line extends is greater than the maximum value of the width of the area; the two reinforcement portions and form a casing shape; the reinforcement portions and has such an anisotropy that they stretch less easily in the direction along the first center line while stretching more easily in the direction perpendicular to the direction; the upper end portion of the area is placed anterior to the lower end portion of the area; and respective upper ends and of the first and the second reinforcement portions and are continuous with an engagement portion with which a shoelace engages, and respective lower ends and of the first and the second reinforcement portions and are continuous with an upper surface of the sole.