The operator of popular all-girl band AKB48 and its sister groups said Monday it has removed one of its officials from a key post amid criticism of its handling of an assault against a member of idol group NGT48.

The company, AKS, announced the change in personnel and issued an apology five days after Maho Yamaguchi, a 23-year-old member of NGT48, revealed that she had been grabbed by the face by two men at her home on Dec. 8 last year.

Despite being the victim, Yamaguchi was made to apologize to fans during a performance on Thursday for revealing the incident on Twitter and thereby "causing trouble."