Teacher of World Literature, and also the homeroom teacher of Class 2-D.
Sastran Zehs is a child genius, a savant, to the point where she makes other child geniuses pale in comparison. Armed with eidetic memory, she has memorized more books in her mind than there are in most libraries around the world. In theory, this should make her a perfect teacher in the subject of World Literature... but in actuality, she's still a child; with all that entails.
Her lessons can be sometimes informative and sometimes confusing, depending on what mood she is.