Edit
A term for shoulder bags and backpacks extensively covered in anime merchandise. Most commonly, these have a plastic window where merchandise can be displayed inside.
They are a common aspect of oshi-katsu, where they are decorated with merchandise of a particular idol or character.
Most often, they feature a large number of button badges, and may even have small character dolls placed inside.
Examples
See Also
No posts found.
1

Pixiv
Twitter
Bluesky
Weibo
Lofter
Tumblr