Ataru, who suffers from "savant syndrome," has the power to discover, observe, see through, and deduct microscopic evidence of unsolved cases. Why does he always go to the criminal sites? What explains his strange behavior? His sad past will be revealed as the story unfolds. An explosion occurs at a chemical factory, leaving one person dead. The investigation team concludes that it is merely an accident, but Ebina Maiko has her doubts. When she goes to the site again, she finds a man who introduces himself as "Chokozai." After blurting out a series of words that Maiko cannot understand, he suddenly falls asleep. Maiko decides to look up the meaning of these words. She is taken aback when she discovers that when put together, these words provide the key to solving the case.