In Kusunoki no Bannin, twenty-something Reito Naoi is wrongfully dismissed from his job, sparking feelings of rage and a desire for payback. He devises a plan to steal a prized object from his old workplace, but the scheme fails and he is taken into custody. While incarcerated, a lawyer contacts Reito and proposes his freedom in exchange for carrying out a task on behalf of a client. With no other options, Reito agrees and learns the client is his own aunt. After discovering he has no concrete plans for the future, she assigns him the duty of watching over a camphor tree located at a shrine. This job leads Reito to uncover the mysterious background connected to the tree.