Conversation so far:
What was J Storm
J Storm, Inc., is a Japanese music and film company owned by Johnny & Associates, was initially as a label for the Johnny's group, Arashi, after which it was named
What caused the decline in sales of singles by Arashi between 2002 and 2005?

Question: What else caused the decline of sales?
Self-contained rewrite: What else caused the decline in sales of singles by Arashi between 2002 and 2005?