Tentoumushi no Otomurai
The story of the animation begins from a girl, named Eiko, mistakenly killing two ladybirds. From this incident, the girl's guilt swells up to create an illusion of seeing a button of her blouse as ladybirds, and fears for a feeling towards an existence of numerous selves in some other places. Being submerged in such continuous wave of guilt and fear, she keeps sewing hundreds of buttons to inside of her skirt.
(Source: Official Website)