The "Cheery Forgotten Umbrella".
Stage 2 mid-boss and boss, as well as Extra Stage mid-boss of Touhou's Undefined Fantastic Object, and Stage 3 mid-boss of Ten Desires. A karakasa youkai who frequently tries (in vain) to surprise humans. She carries with her an umbrella with one big eye and a long tongue sticking out of it; since the umbrella was the traditional description of a karakasa obake, it led to debate as to whether the girl or the umbrella (or both) is the real Kogasa. Fanworks often depict her under the mercy of Kochiya Sanae due to the latter's scathing words against her back in UFO.
Due to similarities in her style of dress to Kazami Yuuka (designated by ZUN as "youkai moe"), along with her being perceived as a highly moe character in her own right, Kogasa is often referred to by fans as "the new youkai moe."
Person: short hair, blue hair, bangs, heterochromia, red eyes, blue eyes, karakasa obake
Clothing: white shirt, long sleeves, juliet sleeves, vest, blue vest, skirt, blue skirt, no socks, geta
Accessories: umbrella, holding umbrella, tongue