This is a flying saucer toy made by Suzuki Vinyl Co. Ltd. in Japan. Dated 1979, the toy was sold in a cellophane bag with an illustrated header card.
This is just a flying saucer with a Superman label, no special embossing or anything. The label features 1970s Superman licensing artwork by Neal Adams. This version of the saucer is yellow, but they were available in different colors. I don’t know that any specific color is more rare or desirable than another.
Here’s a shot of the back.
This detail shot of the front of the card shows a nice Curt Swan illustration of Superman flying, plus the words Flying Saucer 円盤投げ in Japanese and the Superman logo in English.
The back of the card shows a Superman head shot by Swan and a repeat of the Neal Adams flying Superman art. On the right is the Japanese Superman logo スーパーマン with the words Flying Saucer underneath it. The black script below that says “発売元 – Sold at 萬綱商店 – Mantsuna Store.” According to the person that translated it, that store is still active today.