Premium Bandai has recently updated with an official pre-order page for the Buttoba Soul Medal Holder. The Medal Holder features the Kougami Foundation branding and will include 24 Buttoba Soul compatible medals. Most of the medals included in the set are based on the medals that Eiji used in Kamen Rider OOOs, however there are some special OOOs combo medals and a secret medal as well.
Pre-order for the Buttoba Soul Medal Holder are currently open and the item will be released next February priced at 7,344 Yen. Those who are interested should contact their preferred middleman for more details.
Source: Premium Bandai