From Baka-Tsuki:
Blaze is a weapon made by materializing your soul with your enhanced willpower. I, Tooru Kokonoe, have that ability that is said to be possessed only by one in every one thousand people, so it was decided that I would enroll in Kouryou Academy which gives out Blaze and a school that teaches battle techniques. But for unknown reasons, my Blaze didn't have the shape of a weapon but a protector, and it takes the form of a Shield.