Circles, triangles, and rectangles begone. In Konohana Kitan, rhombuses rule as queen.
A peculiar shape, that. Some people refer to it as a diamond (hence the royalty). Others, with technical knowledge of Euclidean geometry, are quick to point out that squares are special exceptions (to said rule).
No matter which side jousts first, this anime makes two ideas clear. One, a rhombus for a mouth makes for a darn cute reaction. And two, our lives have many sides and corners to hold dear.