Masamune is an enchanted swordsman andTsubaki's older brother. The abilities of his family to turn into multiple weapons have been passed down to the eldest child for many generations. However when Tsubaki inherited these traits instead of Masamune, his parents treated him more delicately than nessacery. However it was Tsubaki's pity that eventually drove Masamune to take the sword he had inherited from his father and become an enchanted swordsman. It can also be seen that, as well as becoming a Kishin, Masamune is creating an alternate to the powers he was supposed to inherit by creating his own, thus surpassing Tsubaki.