General: small breasts
Images and animations depicting female characters with smaller than average-sized breasts. This can refer to a cub character in her early teens whose breasts have only just started to develop, or to a fully-grown character whose breasts just aren't very big.
This does not refer to a female character who has not developed breasts yet, or to adult females who are depicted without mammaries at all. For these situations, use the tag flat_chested.