This is the R18 version which includes adult sex scenes! Based on a teens-love manga by Onigiri Musubi.
Ookami had her skirt swiped by the rumored "skirt bandit." Her teacher Akagashira happened to be passing by and came to Ookami's rescue. Akagashira took Ookami home, but Ookami had a real reason for bringing Akagashira there... "Stuck with a girl in a room with the lights out, I ... can't help myself!"