Though major publishers abandoned the PSP long ago, Sony's handheld is the best place to find Japanese strategy-RPGs and the like thanks to the localization-mad publishers like Aksys and Atlus. Aksys yesterday announced it's bringing yet another SRPG over to the PSP this year, Ragnarok: Tactics by Chime and Apollosoft.
Based on the world of the Ragnarok MMO, Tactics offers the usual strategy RPG fun: a story of one hero in the midst of an epic war, customizable characters, special abilities, multiple endings and what have you. You can also swap weapons with other players in ad-hoc multiplayer, and battle units they've created.
Aksys has an official site for it, but it's all very placeholder.