Dubbed the "Wristunder" (geddit? GEDDIT?), the special panties were invented by Chiaki Takahashi, the voice actress who brings life to video characters in The Idolmaster, BlazBlue and many more.
Takahashi is dubbed a "sexy voice actress", and it often seems like she tries really hard. Probably too hard. But, hey, she tries. There's always trying.
For the launch of her new photobook, she showed up dressed as Marilyn Monroe, and presented her invention, which was the result of the desire to create a "sexy item" which helps promote her new pin-up book, while not leaving her male fans out. And voilà, panties men can wrap around their wrists, while they attend Takahashi's events.
While this seems like a publicity stunt (it is!), My Navi reports that Takahashi is currently applying for a patent, should anyone decide to ever try to steal her idea. You know, the one in which people wear underwear on their arms in public.