A Kaikaku event is there to facilitate a serious system change to grow product development capabilities within an organization. One can go with Kaizen events and related incremental improvement until the limits of the system you apply them in, in order to improve further one will need to apply some kind of Kaikaku or choose to get stuck. In this talk with participants from 2 different organizations we supported in their LeSS (Large-Scale Scrum) Kaikaku, you will get some good insights in how to approach such an event, how such an event could look like and what comes after it.