Fukuro is actually a very cute sub-character that also exists in Sumikko Gurashi.

Fukuro is very close friends with Suzume, a character in Sumikko Gurashi. Although Fukuro is nocturnal, it stays awake during the day just to play with Suzume, which it adores. As a result, it's always sleep-deprived, showcasing its lovable personality.
Usually when it appears, it looks sleepy, and has dark circles under its eyes.

There are times when its eyes are wide open, and it is rumored that these moments bring happiness (fuku).

New merchandise themed on birds was introduced in April 2022, and Fukuro joined the Sumikko Gurashi family. Many adorable products featuring Fukuro alongside Suzume have been released.