This needs an incest tag. It's got some smokin' siscest!

Base +1, sasutore +1

Nearest I can gather: Onee-chan is a teacher who is lusting over her imouto, who is also a student in her class. Various sexy hijinks ensue as a result of the older sister trying to redirect her feelings to other female students.

Ch. 1 "Sweetest Tab(?)" - Overhears a girl getting fucked in the next bathroom stall, then rudely treated by her boyfriend. Attempts to yurify the girl. straight + yuri, bondage
Ch. 2 "Twin Fake" - Another girl in has an identical-twin-of-the-opposite-sex who is apparently a math wiz. She dresses him up as her and sends him to school to take a test for her. Onee-san figures it out. A trap is fine too. straight; femdom, crossdressing:male, nakadashi
Ch. 3 "Kidnap Baby" - Onee-chan sees one of her students apparently get kidnapped. She pursues without calling the police, gets caught as well. "Rape" happens, but "Surprise!" the girl is into rape roleplay. female: bondage, brown skin, strap-on, small breasts, large breasts, anal, double penetration; male: glasses; mff threesome
Ch. 4 "White Christmas" - In which the class-president get plowed. Pantyhose that fail to be torn open make me a sad panda. yuri, glasses, pantyhose
etc.

Not that bad.

Base +10, cookiedog +6