昊陵学园是一所武术训练学校，九重透流身世悲惨，他希望到武术学校加强训练让自己变强大替死去的妹妹报仇。而九重拥有一千人才出一人的技能“焰牙”，拥有此技能的人可以凭借精神力把自己的灵魂具现武器当中，战斗中这种武器将实现人器合一，武器变得有灵魂而威力无比。然而让九重郁闷的是，他“焰牙”的不是武器而是防具。就这样九重不能例外地必须遵守校园的“绊双刃”制度，必须与另外一个学生结成“绊双刃”。“绊双刃”制度就是要求学生结成对子，两人同吃同住加深彼此羁绊，只有这样两人得到的力量就会更加强大，而且羁绊越深力量越强大。九重与一个女孩结成“绊双刃”，从此后，九重开始了跟美少女茱莉的同居生活。除了九重，他身边的其他性格各异的同学莉莉丝、橘巴、穗高雅，这些女孩们都将在学校找到属于她们的相伴一生的羁绊…

Hao Ling Academy is a martial arts training school, Kunou Toru has a tragic life experience, he hopes to strengthen training in the martial arts school to make himself stronger and replace the dead Sister revenge. Kokonoe has the skill "Blaze", which can be produced by one person out of a thousand people. People with this skill can use their spiritual power to manifest their souls into weapons. In battle, this weapon will realize the integration of man and machine, and the weapon will become a soul. And the power is incomparable. However, what makes Jiuzhong depressed is that what he "flames" is not a weapon but an armor. In this way, Kunou must abide by the school's "tripping double-edged" system without exception, and must form a "tripping double-edged" with another student. The "Two Blades of Bonding" system requires students to form a pair, and the two eat and live together to deepen their bond with each other. Only in this way, the power they get will be stronger, and the deeper the bond, the stronger the power. Jiuzhong and a girl formed a "tripping double blade", and since then, Jiuzhong began to live together with the beautiful girl Julie. Except for Kunou, Lilith, Tachibana, and Sugoya are other classmates around him with different personalities. These girls will find their lifelong bonds in school..