Newly adopted orphan Hitori Sonoyama appears to be the perfect child: Sweet, loving, and adored by his new parents. But the truth is "Hitori" is not real; he's a role played by identical twin brothers Migi and Dali. Determined to find a way back to the place of their birth to avenge their mother's death, they've wormed their way into the hearts of an aging couple who live there by pretending to be one seemingly angelic child. But upon their arrival, they'll need to investigate the village and its residents to figure out who the murderer actually is, all while doing whatever difficult, painful, or bizarre things it takes to uncover the truth and make sure no one discovers their secret in the process.