Taboo Tattoo

Middle school student Seigi, who has training in martial arts, frequently feels compelled to defend those who are weaker than him. He once defended a homeless man from some punks, and in appreciation, the man gave him a bizarre tattoo on his palm. A covert weapon created in the arms race between the United States and the Serbistan Kingdom is the tattoo. When a strong girl utilizing the same hidden weapon brutally pursues Seigi to get it, Seigi finds himself in over his head. Will he be able to figure out how to activate the power of his tattoo in time, or will his martial arts prowess not be enough to keep him alive?