After the success of her first movie Atchoum en cavale (Atchoum on the Loose), Atchoum returns, to the delight of children. We catch up with Atchoum, happy to be home after touring with her show. But when she arrives, she is horrified to see her room is messy and dusty, just as she left it. Now, like her parents asked her to, Atchoum has to clean up. In trying to put off the task at hand, Atchoum embarks on a series of adventures that take her on a colourful and musical adventure to a universe that is full of lively songs from her recent music album Le grand ménage.