JO1's Shiroiwa Ruki has tested positive for COVID-19, and has cancelled his appearance in the event 'All Night Nippon 55 Shunen Kinen All Night Nippon X Special Live 2023' on the 15th. In place of Shiroiwa, fellow member Sato Keigo made an appearance. 

According to the group's official website, Shiroiwa had a sore throat and felt ill the other day so he conducted the PCR test which confirmed him positive for the virus. He is currently isolating and recuperating under guidance of the public health center. 

LAPONE Entertainment commented, "We apologize for the inconvenience and concern caused to everyone who looked forward his appearance, as well as to all persons concerned. We kindly ask for your understanding."