ABSTRACT
The lesson study open house held at Tsuta illustrates one of the ways in which Japanese teachers connect with colleagues outside of their group in order to extend the learning opportunities that lesson study affords them. Open houses not only allow those organizing them to enrich their lesson study work, but they also provide many learning opportunities for those in attendance, and by extension, the respective lesson study groups that they represent. These benefits explain why some open houses can be quite large, particularly when they are hosted at schools with a good reputation. Most notably, national schools regularly hold open houses, which sometimes are attended by thousands of teachers from all over the country. 1
