This study used interview and observation data to investigate how school principals approached both the promotion and implementation of lesson study. Using distributed leadership and sensemaking, the study found that the principals received a lack of formal guidance and they used prior knowledge to adapt the model. To capture buy-in, the principals distributed leadership as a mechanism to bridge the gap to teachers while simultaneously empowering teacher leaders. In an environment of instability, the principals also utilized distributed leadership to sustain and scale up of the reform initiative. However, a dichotomy of distributed leadership was evident. "Active" principals offered direct support to the teams while "passive" principals allowed the teacher leaders to run the lesson study without any principal interference.