Called Fugu no Hi (ふぐの日), the name is pun from the combination of 2 (fu) and 9 (kyu which is close enough to gu).
For this fish more poisonous than cyanide (Wiki), previous reports of fugu fun on the 3Yen include:
- Fugu blowfish disco ball (3Yen / 2007)
- Japanese raw death with a guarante (3Yen / 2006-03-14)
- Help break fugu-liver taboo (3Yen / 2005-05-09