Soft objects are widely used in our day-to-day lives, and provide both comfort and safety in contrast to hard objects. Also, soft objects are able to provide a natural and rich haptic sensation. In human-computer interaction, soft interfaces have been shown to be able to increase emotional attachment between human and machines, and increase the entertainment value of the interaction. We propose the FuwaFuwa sensor, a small, flexible and wireless module to effectively measure shape deformation in soft objects using IR-based directional photoreflectivity measurements. By embedding multiple FuwaFuwa sensors within a soft object, we can easily convert any soft object into a touch-input device able to detect both touch position and surface displacement. Furthermore, since it is battery-powered and equipped with wireless communication, it can be easily installed in any soft object. Besides that, because the FuwaFuwa sensor is small and wireless, it can be inserted into the soft object easily without affecting its soft properties.