Square-Enix's Japanese e-store has released information on a box set set to be released in Japan on April 29th featuring key rings based on the medals from 'Kingdom Heart Unchained χ[chi]'. Priced at 5,770 yen (roughly $51), the medals (shown above) include KH2 Mickey, Organization XIII Roxas, Axel, KH3D Sora, Donald Duck, KH1 Riku, KH1 Cloud, and Shadow Heartless. No word if the box set will be released internationally.
Thanks to @tamale for the tip!
'Kingdom Hearts Unchained χ[chi]' Medal Box Coming Soon to Japan