Chronologically, Days is the second game because it starts a little before CoM does. In terms of release, Chain of Memories is as it was released on GameBoy Advance in between KHI and KHII. As far as main games, KHII is the second game.
Various Kingdom Hearts-styled accessories have been recently made available to pre-order for limited availability on the geek merchandise shopping site, Merchoid. These items include a sidekick bag, a zip purse, a necklace and earring gift bo.
Complete Kingdom Hearts Chain of Memories - Game Boy Advance