In case you couldn't get enough browser-based games and oddly named Kingdom Hearts entries, Kingdom Hearts X[chi] is coming to browsers soon in Japan. As indicated in the trailer above, the game will utilize a chibi-esque artstyle, and will feature old worlds re-used from prior games, including Agrabah, the Dwarf Woodlands, and Wonderland.
X[chi] will allow you to customize and upgrade your own hero as you battle with the game's card-based combat system and take on select enemies with friends. If you're interested, you may be able to get in on the Japanese beta in the near future.
Kingdom Hearts [Twitter]