Also known as: 黒薔薇女子高校
The school uniform worn by students at Kurobara Girls' High School in Go-Toubun No Hanayome.
A Serafuku consisting of:
a black blouse with White Sailor Collar and grey neckerchief, and a white pleated skirt; or
a white blouse with Black Sailor Collar and neckerchief (color unclear but presumably grey), and a black pleated skirt.
Presumably one is the summer version and the other is the winter version.
Fanart often shows the neckerchief in colors other than grey.