User blog comment:Lamango/IS IRONKING AND SILVER KAMEN TSUBURAYA MATERIAL!?/@comment-1733689-20130902044210/@comment-5951231-20130903114818

He didn't work for them per say, it was a joint production with his company Dynamic Productions.

Silver Kamen had some of the same guys who worked on Ultraseven during the shows second half in an attempt to retool the show and boost the ratings. Needless to say, the plan backfired and the show was cancelled.

Because some of the people who worked on Ultraseven worked on that show, people get confused and think it was made by Tsuburaya.