Takamagahara

Inside of every human lie dormant superpowers. When these powers are awakened, some people use them for evil. Others use their power to stop those who commit evil deeds. One cruel boy named Hiruko has taken over his high school by using his superpowers. The students live in fear of him, until the day a mysterious transfer student, with his arm wrapped in a giant cast, arrives to stop him...
(Source: MangaHelpers)