Di Gi Charat: Natsuyasumi Special
The Di Gi Charat Summer Special was a four episode series that aired over two days, August 22, 2000 to August 23, 2000. This was the first series that Piyoko appeared in and the plot involves her attempting to hold Dejiko hostage for ransom.
• Episode 1 - Here comes Pyoko-nyo!
• Episode 2 - It's the Black Gamers-nyo
• Episode 3 - The Return of Abarenbou
• Episode 4 - Summer Bug
(Source: AniDB & Wikipedia)