Kurobara Girls High School

Kurobara Girls High School (黒薔薇女子高校) is an elite all-girl school typically attended by rich families. Nakano quintuplets spent their first year of high school in this institution.

History
Among the Nakano quintuplets, Miku bears the most hatred towards this school.

It was mentioned that Yotsuba failed the final test in the school and rather than moving up, her sisters' decided to join her and repeat the year before they eventually switched to their current school.