Despite popular belief, there are lizards in this world that cannot regenerate their tails. Does that mean humans are the same? Are there humans out there who can actually regenerate entire limbs, even though such a feat should be impossible? Shuu whispered quietly to himself, While everyone else on the train platform were screaming and running away in a panic. On the train tracks before him lay the shredded remnants of a young girl's body. She had been squished by a train just moments ago. After that day, Shuu's experiments began... - Translated from the official summary by Dergonu