PhD Phantasy Degree Vol 5

PhD Phantasy Degree Vol 5 by Son Hee-Joon. A Fantasy manga rated Teen, published in English by Tokyopop in 2006.

Sang is a spunky, fearless girl with a big secret: she's human, and she is determined to get into Hades, a demon school that admits only monsters. After talking a band of misfit monsters into taking her there, she goes to wild lengths to pass as one of them, all in search of a mysterious ring. A rowdy Korean fantasy comedy from Son Hee-Joon.