hasu no shoushihenkei

The 104th year members of Hasu no Sora Girls' High School Idol Club as of the 105th year, consisting of Momose Ginko, Kachimachi Kosuzu, Anyoji Hime, and Katsuragi Izumi.

Their name literally translates to "Hasu's Little Quadrilateral", expanding on the Hasu no Shousankaku's "little triangle" to include Izumi.