The group at 3:29 not 3:30 Seen better at 10 seconds in

Those are the characters that appear at 3:29, you must be referring to the group at 3:28. Unfortunately, I don't know those characters by sight. The most I could find out was that these characters are most likely of Chinese origin. They might be original characters that got a following, or they might be mascot characters for a website or product, or they might all be from different places. Because they're Chinese, they won't be listed on any anime/manga sites because they're not Japanese. Unless you can find someone who already knows who the characters are or who can read Chinese, you might be out of luck.

Perhaps he's thinking of Touhou project?