Yukiko Misuzu

Yukiko is the school nurse who tended to Asaki Hiroki and Shion. She becomes more interested in Asaki after she visited him the day he was run over by a truck without being hurt. She later becomes Shion's rival for Asaki's attention. She's also considered the school's idol and was the most popular girl among the guys, at least until the appearance of Shion. However, she is also Hebi, the Snake Geist with the power of venom, whose bites can turn Geist infected people into complete Geists within 24 hours. She can also manipulate the entire bodily fluids of someone with the use of her mouth.