Following the death of their parents in a tragic car accident, Haruka Kasugano and his twin sister Sora are left orphaned. Rather than live with relatives, Haruka seeks comfort in fond memories of the past and decides to move to the country house left to the siblings by their grandparents, who are also deceased. Sora, unwilling to be separated from her brother, decides to follow him. Although Haruka's glad to relive the memories of the summer vacations he spent at his grandparents' home, Sora's much less enthusiastic.Haruka reconnects his childhood friends Nao Yorihime, the neighbourhood older sister, and Akira Amatsume, the shrine maiden. He also becomes friends with his new classmates Kazuha Migiwa, the daughter of a local politician, and Ryouhei Nakazato, who is in Haruka's class because he ended up getting held back a year. Haruka also meets Motoka Nogisaka, a maid in the employ of Kazuha's father.Originally designed as an H-game, Yosuga no Sora averts the standard Unwanted Harem by having a player express interest in a heroine early on in the game. The story then branches off and shows Haruka's developing relationship with the chosen girl. Each route's a story of drama, summer love and coming of age as Haruka adapts to his new responsibilities as Sora's de facto caretaker and learns how to provide the heroine with emotional support.Currently has a manga and a 2010 twelve episodeAnimated Adaptation using a similar episodic format akin to Amagami SS: each heroine has an "arc" dedicated to her, but rather than an Alternate Continuity to reset an entirely new "arc", the next set of episodes features a What If? for Haruka in vying for another heroine's heart.A sequel/expansion fan disk called Haruka na Sora contains bonus material, extended scenes and includes scenarios for Kozue Kuranaga and Yahiro Ifukube.
Beyond the Impossible - Kazuha and Akira being born on the same day from different mothers
Big Damn Heroes - Nao, when she jumps into a burning bus stop to rescue Sora's rabbit doll, kicking down the large board locking her in after a few seconds of suspense. Not bad, considering that Sora hates her after catching her years ago in the act of (presumably) raping her brother
Bittersweet Ending: At the end of the Sora arc, both Haruka and Sora move away from the town to an unnamed foreign country in the hopes that they can find a place where their incestuous relationship will be accepted. Whether they actually find happiness or not is left ambiguous. Meanwhile, Sora's arc is the only one that explicitly shows that Kozue is left an emotional wreck when she realizes that Haruka won't return her feelings.
Episode 6 practically goes all out at showing Akira in all sorts of kinkysurprising sex positions.
Broken Bird - Yes, Sora could probably use a slap or two for her selfish, needy behavior. On the other hand, she's such a psychological mess that it's hard not to feel sorry for her.
Bromantic Foil - Ryouhei, who often teases Haruka that he (Ryouhei) wants to be Sora's escort. Doubles as the Unlucky Everydude
Conspicuous CG - Most car scenes are the blatant ones (the train scene, too) but ESPECIALLY THE FANS, where it seems the animators spent a lot of time in the initial scene showing you the fan on the train. You could say that this show has its own fandom. Heck, even a Photocopy machine...
Cool Big Sis - Nao, Yahiro and Akira by a few minutes
Continuity Nod - The omake ED includes Yahiro and Kozue as part of Haruka's harem, even though their actual arcs were only included in the game's fandisc
Date Rape: What Haru nearly does to Nao in Sora's arc.
Erotic Dream - Late in Sora's arc, Haru dozes off in class and dreams that his sister has snuck under his desk to give him a blowjob.
Festival Episode - The summer festival is a common event in the game and anime
First Kiss - Haruka and Kazuha have theirs by the third episode, initiated by the former. While it seems Kazuha would resist, she actually gives in and implied her feelings to him in response
Likewise, Akira willingly gives this and more in the Furo Scene of episode 5.
Follow the Leader - Semi-averted: while it seems like it follows the story-telling plot from Amagami SS, where after one arc is over and they Retcon the entire thing with the next heroine, Yosuga no Sora splits from the end of episode 2, rather than episode 1, for Kazuha and Akira. Nao and Sora's arcs split from the end of episode 7
Foot Focus - The anime absolutely loves showing bare feet and legs. Especially Sora's.
Foreshadowing - The Motoka omake scenarios show bits and pieces of the main heroines' plots. To note:
When Sora comes out underneath Haruka's desk and the next scene has her and a few other girls eating a lollipop.In Sora's route for the visual novel, she gives her brother head during class.
When Sora and Nao get into a brawl with the shed on fire due to lightning, it features the same scene but this time, Nao rescues Sora's rabbit doll from the burning shed in Nao's arc.
For a split second, the twins were drowning in a lake all Super-Deformed. During Sora's arc, they do nearly drown in the lake.
Which leads to Wild Mass Guessing as to who rescued the both of them (although, it's implied to be Nao because of the ending sequence).
It was self-rescue, and by Sora: in the visual novel, Haruka said "Help me" at the very last moment before completely drowing, giving Sora a reason to live. She ends up saving him by herself, which also explains why Sora is on top of Haruka when he regained consciousness and that there's only the two of them in the area. Cue an H-scene involving the two a few clicks later.
Gainaxing - Quite a bit in the anime, especially the second ED, which has Nao/Motoka/Yahiro all bouncing their goods in unison
Gender Blender Name - The fact that Haruka and Sora are both unisex names with feminine bases just makes the whole thing weirder
Genius Ditz - Akira's usually a klutz, but she's extremely perceptive when it counts.
Hilarious Outtakes - The entirety of the Motoka omakes, although some scenes serve as foreshadowing for key events in the main girls' routes.
Hot Mom - Yahiro can be considered this: she looks after Akira after the death of her foster father
Hotter and Sexier - In comparison to the rest of the post-midnight anime market, anyways. Whereas most networks still shy themselves from showing uncensored nipples after midnight, Yosuga no Sora dares to go the whole nine yards and show full sex-scenes on network TV, akin to HBO's Rome and The Sopranos
Idiosyncratic Episode Naming - Every episode works in the name of a character or two while keeping the title an actual sentence. A prime example is episode 4: while translated as "Haruka's Heart", in katakana it's spelled "Harukazuhaato", containing both "Haruka" and "Kazuha" (the episode's two main players) in the title
Idiot Ball - Why didn't Haruka's grandma confirm with Kazuha's parents whether the babies were switched instead of telling Akira in her diary?
Ill Girl - Sora, but it never really comes up, except in the manga
One early scene in the anime has Sora spend time at the hospital when she was younger. Haruka also briefly mentions this during Sora's arc.
Immodest Orgasm - Motoka, which is unfortunate given that she lives with her parents
Innocent Fanservice Girl - Akira pretends to be this. But from the looks of it, she's very well aware of what she's doing.
Sora is this to an extent, especially in her own arc (though she isn't all that innocent by that point). And her room is definitely fan serviced.
Les Yay: Before The Reveal about Kazuha and Akira's relationship as sisters, Haruka finds himself fantasizing about the two of them as lovers. Kazuha is revolted when she realizes that's what he thinks. But significantly, Akira is willing to force a fairly passionate kiss on her in order to make a point ...
Little Sister Heroine - Sora. Possessive and prone to thinking of him during 'special' times, she actually is related to him by blood.
Mood Whiplash - The omakes at the end of each episode is... out of place with the episode preceding it
Gets even more ridiculous when the chibi-like figures shape-shift, such as Motoka's snakish figure in episode 3. Or Akira's head being GINORMOUS. Coincidentally, these are also seen in the second ED.
My God, What Have I Done?: Nao thinks that she might have raped Haruka (depending on if you interpret his "behaviour" afterwards as Post-Kiss Catatonia or traumatization, she's right). She carries a burden of guilt for several years before things clear up.
Near Rape Experience: Haru nearly rapes Nao in Sora's arc at a Love Hotel due to his frustration over his sexual attraction for Sora. He stops however after hearing Nao's crying and screaming for him to stop.
Non-Identical Twins - Subverted: Kazuha and Akira share the same birthday and father, just not the mother
Norse By Norsewest - At least in the manga, it's implied that Haru and Sora ended up moving away to somewhere in Scandinavia where they could finally live together in peace.
Sort of: he's not openly supporting her because it would hurt Kazuha's mother more than he already has, while he does give her the attention and support of a father in secret.
Kazuha's mother plays a subversion in this to Akira. When Akira was born, Kazuha's mother would sometimes play with her, because her real mother would not do so (and later revealed to have passed away, anyways). She gave her pendant to Akira in the hopes of letting her feel a mother's love, but later in life, Kazuha's mother would neglect Akira due to the implications that she was her husband's illegitimate child. She gets better at the end of Akira's route.
Primal Scene - Why the already-clingy Sora has a special hate for Nao: she walked in on them having sex several years prior. And in episode 8, it happens again.
Poor Haruka. Episode 11 takes this up to, well, eleven. It must be pretty darn awkward for a guy to have two of his classmates (one of whom is his ex-girlfriend) walk in on him taking his sister from behind in the entryway of their house. At the exact moment that said sister orgasms.
Sort of a subversion on both parties: Nao genuinely regrets what happened and thought Haruka hated her for it. Turns out it was okay for him (he was just surprised from it since it was his first time) and he wanted both of them to get over it. Depending on how you see it, it may or may not overlap with Rape Is Love.
It helps the anime is a lot less clear on whether or not the incident was consensual, and Sora is very biased on the matter.
Rape as Comedy: Matoka does this to Haruka in episode 7's omake while drunk. Not that Haruka minds it...
Squick - In-universe: Haruka was revolted and ultimately driven to tears at the sight of Sora masturbating while moaning out his name.
Stepford Smiler - Akira. Her mask fades when she's alone, when she's reminded of her mother, or when she sees Kazuha's mother. The last one has her coming close to breaking down
Coincidentally (or perhaps, not-so), Akira's personality mirrors that of the goddess worshipped by the town "Sayori-hime". Naturally, Akira's dance at the summer festival is a tribute to the goddess.
Resolved even faster with Haruka/Akira as of episode 5. It took her only half an episode for Haruka to remember her and for Akira to jump him in the bath. This may possibly be the fastest resolved sexual tension yet.
Untrusting Community - Notably averted: the members of the community in general were greatly indebted to the Kasuganos' grandparents and are more than willing to help them out. In the Sora arc, the main reason the Kasuganos decide to leave the village was due to the taboo nature of their relationship (and the fact that Nao and Kozue caught them having sex).