Yes, there is. The official
fun club is "Modern ét la".
The member's privileges are the priority booking for the concert ticket and to
issue the bulletin (this is so good, but Japanese only).
You need a membership fee 5000yen per a year.
The address is
Modern ét la club
zip 530-0041
c/o Hip Land Music
Seto-building 701
3-8-9 Ogi-machi, Tenjinbashi,
Kita-ku, Osaka-shi, Japan
If you have an interest, send a letter to here. But I'm not sure whether they can reply by air mail or not.