We proposed the “Tactile Clip,” a device to induce an illusion of softness, and verified its effectiveness in augmenting softness perception. A Tactile Clip is a wearable device that provides circumferential-force stimulation to the feet. This force results in the deformation of the foot skin, consequently influencing the perception of softness. We conducted a psychophysical experiment using the interleaved staircase method. Twelve participants assessed foot softness by comparing the stepping sensation of the reference sample with the Tactile Clip to that of the test samples without the Tactile Clip. From the response rate, we derived a psychometric curve and bias value. The results showed a significantly positive bias in the perception, suggesting that the Tactile Clip made the flooring material feel softer than the actual softness. We consider the factors contributing to this phenomenon as a slight increase in the foot’s thickness by deformation of sole skin and/or cognitive effects due to changes in force stimulation on the side of the foot in response to stepping.