Unexpected value for parent SKU [%s]. For help with this error, see http://sellercentral.amazon.co.jp/gp/help/24761
This error occurs when your data associates a child product with a parent item other than its current parent. You cannot associate a child product with a new parent item without first deleting its relationship to an existing parent.
Common reasons why this error may have occurred include the following:
If you received this error after posting a relationships feed (XML), please see Deleting a Relationship in Relationships Feed Overview for more information on how to delete a parent/child relationship.
When you have deleted the existing parent/child relationship, you will then be able to create the new parent/child relationship.