The Gudetama cafe in Tokyo was only temporarily opened from November 4 to January 15. But don't worry, if you still want to eat in one, there's a cafe in Osaka. Even if you're not a fan, these are worth going to.
Unfortunately, there is not enough information floating on the web, but you can check out RocketNews24 for more details on the food and cost.
Here's some info about the location in Osaka on DigJapan.