Kotohime is one of the few PC-98 characters who has a full in-game portrait. (The portrait appears when she is casting a special attack.)
She could've been part of the inspiration for Kaguya Houraisan, as Kotohime means "little rabbit princess", and Kaguya resides in Eientei, a place filled with many, many rabbits. They're both princesses, and neither apparently go out much. And they're both strange in their own ways... Furthermore, Kotohime's theme music is "Maniacal Princess," while Kaguya's is "Flight of the Bamboo Cutter ~ Lunatic Princess."