Katanagatari, hmm? Sounds a bit like Bakemonogatari; and by no small coincidence. Both of these light novels were originally authored by NisiOisiN, however Katanagatari is being adapted by another studio called White Fox, as a series of monthly specials starting from January 2010. The story centers on Shichika Yasuri, the seventh generational head of the Kyotou-ryuu school of martial arts in medieval Japan. He and his older sister Nanami live on an isolated island, until a military advisor named Togame tells him of the final 12 swords forged by a legendary swordsmith. At Togame's bidding, Shichika embarks on a journey to find all 12 of the swords. (based on ANN synopsis)