Ukifune wanted to commit to leaving her world, the world of the court in Heian Japan. She did so by taking vows that would preclude her return to the secular world. First, the rules of her commitment are easily stated: she must live in a convent and not range into the larger world. Second, her actions were extremely easily monitored. If she left, her absence would be instantly noticed by the small group of her fellow nuns, and her presence elsewhere would be instantly seen as wrong even by those who knew nothing of her, because they would be able to see that her hair had been shorn. Third, the sanction against any attempt on her part to return to the court would be essentially of no cost to most of the courtesans, courtiers, and other hangers-on at the court—they would almost all have coordinated on shunning her. The sanction would have been devastating to Ukifune if she had really been intent on returning to the court. Finally, the rules on her behavior after taking vows could firmly be expected to last long beyond her life. They were stable.

XREF: Connects to game theory and credible commitment mechanisms — the logic resembles reputation-based commitment devices described in economics and political science.

Russell Hardin, Trust and Trustworthiness, loc. 246