I Registered as a Low-Rank Bookseller but the Court Seal Keeps Showing Question Marks

Rintarō was used to people coming into his secondhand bookshop to talk about old poems, broken dreams, and stories they could not say out loud anywhere else. That made him good at his work, because he listened when others lied and noticed the books they reached for twice. It also made him the wrong man to inherit a family duty tied to a specific oni that appeared at setsubun, especially when that duty arrived only two days before the festival. Then a prince started appearing at his back alley door, and the quiet life he had built began to crack. A hidden chamber in an ink-stone, an old key he had not touched in three years, and a sealed edict tied to his sibling all dragged him toward a cour...