A wireless power transfer system comprising: a power transmission coil device and a power reception coil device, wherein the power reception coil device is attached to a movable body, for wirelessly receiving power from the power transmission coil device, and the power transmission coil device is configured to oppose the power reception coil device to supply power to the power reception coil device, the power reception coil device comprising: a power reception coil portion including a conductive wire; and a nonmagnetic body disposed between the movable body and the power reception coil portion, wherein the nonmagnetic body includes a first overhang protruding in a first direction (X, Y) outwardly from one end portion of a region onto which the power reception coil portion is projected in a second direction, and the first direction (X, Y) is orthogonal to the second direction in which the power reception coil device is configured to oppose the power transmission coil device, wherein the first overhang provides one or a plurality of depressions configured to provide an increased flow path for eddy currents, and the first overhang is longer than or equal to a maximum permissible misalignment permissible between the power reception coil portion and a power transmission coil portion of the power transmission coil device, wherein the maximum permissible misalignment is a maximal value of a misalignment which can satisfy predetermined power efficiency, or a maximum value of a misalignment which can supply predetermined power. a power transmission coil device and a power reception coil device, wherein the power reception coil device is attached to a movable body, for wirelessly receiving power from the power transmission coil device, and the power transmission coil device is configured to oppose the power reception coil device to supply power to the power reception coil device, the power reception coil device comprising: a power reception coil portion including a conductive wire; and a nonmagnetic body disposed between the movable body and the power reception coil portion, wherein the nonmagnetic body includes a first overhang protruding in a first direction (X, Y) outwardly from one end portion of a region onto which the power reception coil portion is projected in a second direction, and the first direction (X, Y) is orthogonal to the second direction in which the power reception coil device is configured to oppose the power transmission coil device, wherein the first overhang provides one or a plurality of depressions configured to provide an increased flow path for eddy currents, and the first overhang is longer than or equal to a maximum permissible misalignment permissible between the power reception coil portion and a power transmission coil portion of the power transmission coil device, wherein the maximum permissible misalignment is a maximal value of a misalignment which can satisfy predetermined power efficiency, or a maximum value of a misalignment which can supply predetermined power. a power reception coil portion including a conductive wire; and a nonmagnetic body disposed between the movable body and the power reception coil portion, wherein the nonmagnetic body includes a first overhang protruding in a first direction (X, Y) outwardly from one end portion of a region onto which the power reception coil portion is projected in a second direction, and the first direction (X, Y) is orthogonal to the second direction in which the power reception coil device is configured to oppose the power transmission coil device, wherein the first overhang provides one or a plurality of depressions configured to provide an increased flow path for eddy currents, and the first overhang is longer than or equal to a maximum permissible misalignment permissible between the power reception coil portion and a power transmission coil portion of the power transmission coil device, wherein the maximum permissible misalignment is a maximal value of a misalignment which can satisfy predetermined power efficiency, or a maximum value of a misalignment which can supply predetermined power.