There will be a stage play for Chainsaw Man in late 2023. You will be able to watch it in Tokyo and Kyoto from September to October 2023. Fumiya Matsuzaki will write the script. More information will appear at a later date.
Matsuzaki has written for and worked on various stage plays in the past. Previously, he helped to produce the Blazblue Continuum Shift, Super Danganronpa 2, and Prince of Stride stage plays, among plenty of others. So far, he is the only member of the staff on the website for the Chainsaw Man stage play. There is virtually no other information, and tickets are not yet available for purchase.
The Chainsaw Man anime recently ended, and MAPPA had a stream for the opening and ending songs. It follows the story of Denji, who has become the titular Chainsaw Man as a result of his Devil Pochita fusing with him in order to save his life. Denji then becomes a Devil Hunter with the Public Safety Bureau and tries to find a new meaning in life. It is an incredibly popular manga and anime series, with strong sales worldwide.
The Chainsaw Man stage play will be held in September and October 2023, and more information will come out closer to those dates. You can watch Chainsaw Man on Crunchyroll.