This Guardian article examines Japan’s landmark legal reform allowing divorced parents to negotiate joint custody for the first time, ending a decades-long system that granted sole custody typically to mothers and often cut off the other parent from a child’s life. It highlights both the intended benefits, such as improving children’s wellbeing and aligning Japan with other countries, and the concerns raised by critics, particularly around the potential risks for survivors of domestic violence and the challenges of ensuring children’s safety within the new system.