Has Jun Kajiwara ever actually composed for an SNK game or, in general, any game at all? He's arranged and performed for a bunch of SNK albums, this is true, but he's always listed separately from the Shinsekai Gakkyoku Zatsugidan in all the credits, like in
this scan, where arrangement is credited to 新世界楽曲雑技団 and Kajiwara separately. Kajiwara is a frequent
collaborator, but I've seen no evidence that he's an actual
member.