The default costume of Nijisanji EN's Scarle Yonaguni, as seen in post #5522267.
Her default ILUNA school uniform costume comprises a collared white dress shirt underneath a white cropped jacket and tucked under a black corset. The corset also has a checkered red skirt which is also worn over another white skirt. She wears a pair of see-through black pantyhose and a pair of red footwear and black loafers on her bottom half.
Scarle's accessories are composed of a pair of earrings, a gold necklace with a triangle-shaped jewelry attached to it, a gold choker, several bracelets on her left wrist, a red nail polish on her nails (except the ring nails that are polished white instead,) a scepter that rest on a white belt over her waist, and another black belt worn over her corset. From the reference sheet, Scarle also wears a black bustier underneath her shirt, has the top buttons of her shirt unbuttoned to expose her breasts and cleavage and have few moles on her body, two under her right eye and one on her left breast.
This tag implicates scarle_yonaguni (learn more).