Oniisama e ("To Big Brother") is a Yuri Genremanga series by Riyoko Ikeda, also the author of Rose of Versailles. Written in the 1970s and published in Shueisha's Margaret, it is one of the earliest examples of the genre, and seems to have had a considerable effect on the series that came after it. It was adapted into an anime series in the early '90s.Told through a series of letters written by the protagonist to her Cram School teacher and older brother figure, Takehiko, it is the story of Misonoo Nanako, an average girl who manages to be accepted to Seiran Academy, a prestigious girls' school for the wealthy and talented. Despite lacking the background and qualifications of her fellow students, she is soon invited to be a member of the Sorority, an elite group of talented and popular girls. This makes her an easy target for the machinations of her ambitious peers — especially one Misaki Aya, who will do anything it takes to discredit her so she loses her place in the Sorority. And as time passes and Nanako meets more people, she becomes embroiled in the drama and complex, often angsty relationships between them.And that's only the tip of the drama iceberg.
Ascended Extra: Tomoko gets much more facetime in the anime than in the manga, mainly thanks to a specific early incident being changed.
Adaptation Expansion: The anime adds quite a bit more to the manga's storyline. To give some perspective, the manga is only three volumes, while the anime consists of 39 episodes.
Anguished Declaration of Love: Nanako delivers one to Rei. Fukiko also gives one to Nanako, although it turns out to be fake.
Bait-and-Switch Credits: The opening credits seem to be sort of thing suited to Shojo anime, but after Episode 11 and Rei's apartment are seen, they take on an eerie new significance. Even more so after episode 23, where we see Fukiko's Room Full OF Crazy....
Bait-and-Switch Lesbians: Kaoru aka Kaoru-no-Kimi (marries Takehiko in both manga and anime, with different results on each continuity), Mariko (implied to enter a relationship with Fukiko's brother Takeshi, though only in the manga), Fukiko (revealed to have loved Takehiko all along, then deciding to remain celibate after Rei's death and Takehiko hitching up again with Kaoru). Nanako subverts this: in the manga there are no hints of anything aside of her mourning for Rei, but at the end of the anime she mentions that she fancies a "university student" — but we don't know if said student is a boy or a girl, since in the original Japanese she uses gender-neutral pronouns when talking about them.
Bifauxnen and Lad-ette: Rei and Kaoru. Both are quite androgynous although Kaoru displays more athletic, tomboyish traits while Rei is more urbane with an interest (and talent) in art and music.
Also, for a middle-class girl Nanako lives with his parents in a pretty large house. Likely to contrast with her "Oniisama" Takehiko's rather simple apartment and Rei's flat with a Room Full of Crazy.
Mariko and her mom Hisako live in a really nice home too. After the Shinobus's divorce, they move out into a cozy but small flat.
Bookends: Early on in the show, several of the school's Mean Girls circulate a petition to have Nanako expelled from the Sorority, for which she was chosen over Aya. Much later on in the show, Nanako herself organizes the petition to have the Sorority disbanded.
Episode 15 also shows the devistating social/emotional consequences of being kicked out of the Sorority due to failing midterms, like it happens to Mariko and Nanako's classmate Junko Nakaya — which also affects Nanako quite a bit.
Bury Your Gays: Rei, the only major character to not get handed the Bait-and-Switch Lesbians card. (Nanako's ambiguous case notwithstanding). The circumstances of her death differ between the two versions: suicide via drugs overdose in the manga, a train accident in the anime (though people think she killed herself at first).
Chekhov's Gunman: In the first scene of the anime, Nanako reminiscences about a pre-teen boy she once saw when she was a little girl, and who ran away from her when she tried to talk to him. That boy is young!Takehiko... her stepbrother.
Crash into Hello: How Rei and Nanako meet: Nanako had trouble trying to get off the bus in the first day of school, Rei pulls her out of there. Later Nanako is running away from other girls and crashes into Rei.
Driven to Suicide: Rei, Fukiko, Mariko, and Aya all contemplate or attempt it at some point, and in the manga Rei actually completes it (in the anime, she dies in an accident). Rei's mother also died by drowning herself in the ocean.
Elaborate University High: Seiran's campus is only slightly less elaborate than that of Utena's Ohtori Gakuen, for which it was the inspiration.
Even the Girls Want Her: Kaoru and Rei both have sizable female fanclubs. Not to mention Nanako.
Fan Disservice: At some point in the anime, we have Kaoru stripping twice (one of them also including Kimono Fanservice). She's very beautiful, in a Lad-ette way, but both times we see her naked, are in regards to how she had a mastectomy due to breast cancer and is showing her physical scars to others (first to her boyfriend Takehiko, to break up with him; later to her friend Nanako, while explaining her backstory). We don't get to see that, exactly, but the context will get your eyes blurry anwyway.
Earlier, Nanako and Mariko took a bath together after returning home from Mariko's birthday party, which seems to bepretty friendly...if it wasn't for the fact that Mariko goes Yandere on Nanako and threatens to kill her when she wants to return home afterwards. Brrrrrr...
Also, in the anime we're fooled into believing that Nanako and Fukiko will have a Girl on Girl Is Hot-like "moonlight swim". But then Fukiko almost drowns Nanako to scare her off, via hooking her foot under a log and then leaving. She only survives because Fukiko didn't mean to go for the kill and returns to her soon. The scene goes from prospect Les Yay to utterly chilling in few seconds flat.
We're also treated to our fair share of Saint-Juste shower scenes, including one in a later episode where Miya-sama confronts her about their relationship while in the shower.
And Fukiko gets a bath tub scene of angst in the anime, after Rei's death
Gayngst: Nanako has some when she realizes she's in love with Rei.
Hope Spot: In the manga, Nanako is overjoyed when Rei finally confesses that she needs Nanako's support and comfort. The next day, she finds out that Rei has killed herself.
Kick the Dog: Aya does this quite a bit, but an especially good example is when she mocks both Nanako's middle-class background and Mariko's dysfunctional relationship with her father. Doubled when, some time later, she publically annunces to her classmates that Mariko's parents are getting divorced in a very scandalous manner. And then, Mariko massively snaps on her.
Fukiko's abuse of Rei is like kicking a puppy repeteadly. Specially when she tells Rei to wait for her under a tree. During a rainy, cold day. Rei stays there for hours as Fukiko "classily" conducts study sessions, and she fully knows Rei's out there.. No wonder Kaoru hates her so much.
Ogiwara does this when she either tries to slap Junko's friends around for supporting the dissolution of the Sorority (anime), or when she throws a stack of papers at Rei and insults her for saying the Sorority should be disbanded. (manga).
Kick the Son of a Bitch: Mariko may be a clingy Yandere, but you root for her when she slaps Aya around to protect Nanako.
Kaoru gets a huge CMOA when she mauls Aya and her Girl Posse for being mean to Nanako in class.
Knife Nut: Rei/Saint-Juste has rather good aim with her throwing knives.
Love Dodecahedron: Let's see: Mariko admires Kaoru but has a clingy obsession with Nanako and later is sorta tsundere for Takeshi; Nanako loves Rei, who pines for Fukiko, who acts possessive towards Nanako but actually loves Takehiko; and Kaoru also loves her ex-boyfriend Takehiko, who returns her feelings. Phew!
Melodrama: While there is some very real drama in the series, there's plenty of this, too. It is old-school shoujo, after all.
Moral Guardians: The animated series was broadcast on Wednesday mornings in France. Guess what happened after 5 episodes. Not even a Macekre could save it.
Onee-sama: Pretty much all of the eldest Sorority girls play the role, or are supposed to. Lampshaded by Nanako, who comments on how Ogiwara and Komabayashi were kind to her... until the Sorority is in risk of being disbanded.
Room Full of Crazy: Rei has two. One with stuff carved into the walls, one with mirrors everywhere.
Fukiko deserves an honorable mention for the room at her summer house full of creepy dolls and obsessively arranged items of memorabilia from the day she first met her obsessive crush Henmi, which she has since kept completely unchanged for six years and forbids anyone else to enter.
Snow Means Death: Sort of. It was snowy when Rei nearly died in her would-have-been double suicide with Fukiko.
Stalker with a Crush: Miya-sama. Somewhat unusually for this trope, it's not Henmi, the object of her affections, that is the target of her stalker behavior... but Nanako, his pen pal who Miya-sama believes he is romantically involved with.
Yandere: Mariko threatens to kill Nanako and herself when the latter tries to decline staying overnight, then holds the door closed so she can't get out. Luckily Mariko's mother Hisako provides enough distraction for Nanako to escape, but Mariko still protests.
Fukiko has shades of this, in another way. Rather than turning her disappointment against the object of her affections, Takehiko, she turns it against others, like Nanako and specially Rei.
Also, Rei herself may count. In a variation, it's less about possession and more about being VERY obsessed with her sister Fukiko, to the point of being a Love Martyr for her. Since she already has lots of issues, this does not bode well.