Miyuki hummed as she got downstairs, her eyes scanned the place and instantly went to her workplace that she had set out while the girl was recovering. She hummed looking at her friend come down and she pointed at a seat as she took out the girls underwear from her pocket. She took a small fabric and with a very big magnifying glass looked at it as she began to work on it. With a grin she finished it and gently made a cut on the girls panties pushing the small cloth inside as she then saw the pantie back. "It is really simple, when you walk your panties often give static although a you don't notice it since it is a very small amount. What this does its basically to turn the static to vibrations so whenever you walk you will feel the panty vibrating. Want to try it out?" she threw the panties at the girl. The panties seemed to be perfectly normal which made Miyu giggle at the good work.