14-year-old Yuma Nakayama of the Kansai Johnny's Jr. group had to undergo surgery this past weekend, it was learned on Monday. According to his agency, Nakayama complained of stomach pains on Friday night and was taken to the hospital, but he was later sent home. However, the pain continued until Saturday, and this time a doctor diagnosed him with appendicitis and panperitonitis.

Nakayama had an operation the same day to treat the condition. On Monday, he was discharged from the hospital. That same night, he was able to make a brief appearance at a concert, sitting in a wheelchair. It is not yet known if he will be able to participate in Tuesday's and Wednesday's concerts.