Eight diagrams used in Taoist cosmology to represent the fundamental principles of reality, seen as a range of eight interrelated concepts. Each consists of three lines, each line either "broken" or "unbroken," representing yin or yang, respectively. Due to their tripartite structure, they are often referred to as "trigrams" in English.
Most popularly used on Yakumo Yukari's Tabard on her Imperishable Night outfit, as well as Yagokoro Eirin's dress.