Sonic the Hedgehog Birthday Pack, or just the Birthday Pack (バースデイパック, Birthday Pack?), is a limited-edition bundle meant to celebrate the 10th anniversary of Sonic the Hedgehog exclusively in Japan. It includes the original Japanese release of Sonic Adventure 2, as well as a fold-able plaque containing a history pamphlet, a collectible coin, and a disc containing select tracks from previous titles. It was only available for two days – it was discontinued from store shelves on 25 June 2001 and replaced by the standard Sega Dreamcast release of Sonic Adventure 2, making it a collector s item.