Bandai Shogakukan WIZ TV Tokyo, Tamagotchi Chibi, Violetchi

This is a very rare (can't find it on the internet) clip that you would use by removing the screw and threading your ribbon (Tamagochi) lanyard (thin) into the the space between the front and back. The carved out thin piece on the back is where the lanyard went under after removing the screw. The screw was replaced after the lanyard was threaded through and you had no worries of it falling off! It was manufactured by BANDAI.