Synopsis
Seigi is an ordinary middle schooler, notable only for his martial arts ability and strong sense of justice. After he rescues an elderly homeless man from a group of street thugs, the stranger repays him by searing a tattoo into Seigi's palm. That tattoo turns out to be a highly sought-after secret weapon, with everyone—including a formidable girl who bears her own tattoo—in pursuit of it. Facing life-threatening danger and finding his martial arts useless against superpowered opponents, Seigi must unlock the hidden power of his tattoo if he hopes to survive.