Nintendo of America just announced Fire Emblem: Awakening will be released in the first part of 2013 so it might be awhile before you get to play "Summer Bonds." This downloadable mission is scheduled to come out in Japan on November 1.
Anna, who is a merchant in Fire Emblem: Awakening, wants to thank Chrom for rescuing her and invites him to a beach. Then enemies show up and spoil the party. Chrom, Tiamo, Sallya, and Guire will change into swimwear for this map. There is also a special conversation with My Unit, the Fire Emblem: Awakening character that is supposed to represent you. Summer Bonds will cost 200 yen ($2.50) on the Nintendo eShop.