What brand is the little dinosaur pajamas that Li Guangu wears in ipartment?

You should be talking about SAZAC products, not Japanese brands.

But the things on Taobao are too miscellaneous to tell the truth from the false. Many imitations cost 30-40 yuan. Uneven quality

Now SAZAC is in official website, China, but it seems that there are not many things, like preparation. If you like authentic products, you can consider searching Google's "Sadzak" or "Sadzak China".

After all, there are many fakes in China now, and no one knows whether the materials used for clothes are safe or not.