The aim of this study is to consider the significance of exchange learning and joint lessons, which area form of collaborative learning by conducting exchange learning and joint lessons through the online conference system. The three elementary schools signed with the City hall an agreement called “An engagement for the promotion of SDGs” and have built a partnership on the common theme of “promotion of SDGs”. The students in the three elementary schools exchanged their activities and summarized their actions about the partnership in a video. We recognized three effects by analyzing the activities and the studentsʼ reflections on them.