Here lies a listing for the characters, and the tropes applied to them, found in LightNovel/PapaNoIukotoOKikinasai.

The characters' names are sorted in western order (given name, family name).

'''Contains unmarked spoilers, read at your own will.'''
[[folder:Main Characters]]

!!Yuuta Segawa
-->Voiced by: Creator/WataruHatano

[-A nineteen-year-old college freshman who has been living on his own for five years after moving away from his sister Yuri, his only close relative ever since their parents died, after she married Shingo, a middle-aged man with two daughters from previous marriages, to which he naturally objected, but eventually conceded by moving away. A month after entering Tama University as a literature major, Yuri asks him to take care of her and Shingo's three daughters (the youngest of which is their own) for a week while they're on a vacation. The next week, however, he receives news that they had gone missing, and upon learning that his relatives are planning to take the sisters under separate custody, he decides to take these closely-knit half-sisters instead.-]
* AccidentalPervert: Victim of being or doing the wrong thing at the wrong time, to his nieces and Raika.
* AdaptationDyeJob: Yuuta's hair is supposed to be black, with blue outlines for art style; but in some works his hair is completely black.
* BadlyBatteredBabysitter: his role in a nutshell.
* TheBeard: the "emergency" that Miu once sent via text message to Yuuta to fetch her at school: to pretend that he's her boyfriend to ward off her admirers.
* [[BigBrotherAttraction Big Sister Attraction]]: Yuri herself accuses him of this.
* BromanticFoil: a strange example of the main character being one, on account of Kouichi's escapades giving Yuuta grief and sometimes envy to no end.
* CallingTheOldManOut: he calls out the Takanashis on trying to separate the sisters, leading to the events of the series.
* CoolUncle: He is this before a father-figure, after all.
* CrazyJealousGuy: In one chapter of ''Rojou Kansatsu Kenkyuu Nisshi'', he accidentally spots Raika with another guy. He follows them around a bit, and overhears the guy talking to his wife, and concludes that he must be cheating on his wife with Raika, and gets quite upset about that. [[spoiler: Then it's revealed that the guy is actually just a shop owner, and was giving Raika suggestions on gifts for Yuuta's nieces.]]
* {{Determinator}}: Does not give in to demotivational words from those who don't believe he can be a good father-figure.
* GenerationXerox: several times did Yoshiko mention that Yuuta's actions are nothing different from Yuri's.
* HairColorDissonance: Blue to represent black.
* MaamShock: it's a major plotpoint in the early part of the story that Sora calls him "Ojisan" (instead of "Oniichan") alongside her sisters, all because they went off to a bad start. And Yuuta started feeling worse when the girls call Nimura, who is the same age as he is, Oniichan.
* MySisterIsOffLimits: hasn't forgiven Nimura for trying to flirt with Yuri (not that Kouichi had a chance, but still).
* NiceGuy: Probably a big reason why so many girls are falling for him, especially Raika and Sora.
* PapaWolf[=/=]OverprotectiveDad: in the anime, when he learns that Sako is a paedophile at the same time that the latter begins to suspect that Yuuta's got young girls living with him, the first thing he does is ''RUN AWAY''.
* ParentalAbandonment: His parents died when he was a child, his sister Yuri raised him ever since.
* PornStash: and no matter the medium, Yuuri has a knack for finding them instantly.
* PromotionToParent
* SomethingElseAlsoRises: a rare, non-''visual'' example.
-->'''Raika''': ''My head bumped into something hard.''
* YouGottaHaveBlueHair: His default portrayal, still it is supposed to be black, the blue tint is just an artistic choice.

!!Sora Takanashi
-->Voiced by: Sumire Uesaka

[-A fourteen-year-old middle-school girl and eldest of the Takanashi sisters. She met Yuuta five years ago during Yuri and Shingo's wedding, and has since nursed a crush on him after he patches up a wound caused by her stumbling. At school she is shown to be a great singer, having honed her voice by crooning Hina every time she cries, though her natural shyness made her initially reluctant to join her school's glee club. She's also shown to be good at sewing. Due to Yuuta's presence in her life (accidental perversions and all) she, coupled with her secret crush on him, has developed an impulsive side even as she tries her best to help him manage the household.-]
* TheAce: Good at singing and sewing, and acts as Yuuta's fellow breadwinner for the family.
* ACupAngst: ...Especially once she meets [[GagBoobs Raika]]. [[spoiler: 2nd OVA shows that all she had to do was wait.]]
* BedmateReveal: a RunningGag that Yuuta would wake up only to find Sora clinging to him in her sleep.
* BlondeBrunetteRedhead: The redhead to blonde Miu and brunette Hina.
* ClingyJealousGirl: She won't admit it, though.
* CoolBigSis
* CosplayOtakuGirl: Starts to become one with a little help from her otaku classmate. [[spoiler: And, posthumously, Yuri, through the rather extensive collection she leaves behind.]]
* {{Expy}}: Of LightNovel/HaruhiSuzumiya.
* HairDecorations: Wears a ribbon on her hair.
* HopelessSuitor: Due to their age difference, as well as their circumstance, it's highly unlikely that she'll get a shot with Yuuta. Probably won't stop her from trying though. [[spoiler: Averted in volume 18 of the LN and its corresponding OVA special as Yuuta and a now 18-year-old Sora have decided to get married.]]
* IdiotHair
* IdolSinger: in training. The Glee Club thinks of her as their pride and joy.
* LethalChef: She gets better.
* MissingMom: And she's DeadAllAlong.
* [[MrImagination Ms. Imagination]]: so far it's limited to the manga only.
* PottyEmergency: Has a brief one in Epiosde 3.
* ShrinkingViolet
* SingleTargetSexuality: Falls in love with Yuuta pretty much from their first encounter when his sister was introducing him to the her father. [[spoiler:The 2nd OVA makes it abundantly clear that they decide to marry despite their unique relationship.]]
* SitcomArchNemesis: ''Hates'' Sako for [[MaamShock calling her "Obasan" ("old hag")]]. She never forgives him for that little episode, even when he tried making amends (only because he was trying to convince her to help out in the club's SchoolFestival project, a Maid Café).
* SuspiciouslySpecificDenial
-->'''Yuuta''': ''Sora, do you really need that many clothes?''
-->'''Miu''': ''She wants a certain someone to see her...''
-->'''Sora''': ''Onii-chan has nothing to do with this!''
* ThroughHisStomach: as inspired by Saitou Ayana, the focus character in ''Takanashi no Hidamari'' Chapter 3. If you know Sora by now, this went as well as you'd expect.
* {{Tsundere}}: [[spoiler: By light novel 18, she's largely grown past it.]]
* WhenItAllBegan: Her crush on Yuuta began when they first met during Yuri and Shingo's wedding.
** {{Bookends}}: [[spoiler: The second OVA ends with an informal sort-of wedding ceremony between Yuuta and Sora, with the ghosts of Yuri and Shingo giving their blessing.]]
* [[spoiler: WifeHusbandry: Whilte not really intentional on Yuuta's part, it's fully intentional on Sora's: by the time she's 18, they're officially engaged.]]

!!Miu Takanashi
-->Voiced by: Creator/EriKitamura

[-A ten-year-old elementary girl and middle sibling, Miu has inherited her natural blond hair from her Russian mother. Despite her young age, Miu likes to act like a teenage girl, with a savvy for fashion and cosmetics, making her popular in her school. Despite being a boy magnet (and thus the target of many an envious stare from girls), she only has eyes for older men. In spite of all this, she's a good girl at heart, behaving when she need to, and is quick to show concern for others, especially her sisters.-]
* TheAce: Beautiful, athletic, smart...what else could a grade-school boy want?
* AllOfTheOtherReindeer: Her female classmates are jealous of her popularity with boys, retaliating by openly insulting her without even lowering their voices. Luckily for Miu, she has a good female friend that protects her from those girls.
* BlondeBrunetteRedhead: The blonde to redhead Sora and brunette Miu.
* CatchPhrase: always the one to tell Yuuta to "show delicacy".
* [[ChickMagnet Dude Magnet]]
* TheFashionista
* FingerlessGloves: Pink woven ones she wears to sleep.
* GirlishPigtails
* HeroicBastard: Her mother did not even know her father's name.
* MsFanservice: Of the three sisters.
* NotBloodRelated: As it turns out, she is ''not'' Shingo's full-born daughter. She was Sasha's daughter from a man who simply ran on her later. Once Sasha and Shingo's relationship ran its course, Sasha left Miu to him, believing he makes for a better parent than she could ever be.
* PottyEmergency: Has ones in Epiosde 1, 5 and [[BookEnds 12]].
* SchoolIdol: Though she subverts the stereotype of the bitchy social-butterfly in that her best-friend is a chubby and plain-looking girl rather than another pretty fashionista.
* SensualSlavs: Miu-chan does her Russian-heritage proud.
* ShipperOnDeck: Knows about Sora's crush on Yuuta very well, and encourages it in her own strange way. She averts PlayingCyrano, however, since she said that Sora should overcome her shyness on her own to tell Yuuta her feelings herself.
* StepfordSmiler: It's becoming clear that trying to help others is a coping-mechanism to deal with her own personal demons.
* TheTease

!!Hina Takanashi
-->Voiced by: Hiromi Igarashi

[-A three-year-old kindergartener and youngest of the sisters, Hina is Shingo and Yuri's biological daughter, making her Yuuta's only truly blood-related niece. Hina is a bright ray of sunshine to the family (if not the whole series), being an extremely easygoing toddler who can get along with pretty much anyone. Hina not only easily welcomes new friends, but people are attracted by her cuteness, and is one of the reasons Yuuta remains their guardian. Besides her fondness for discovering new friends, Hina also has a love for bunnies in general, including a bunny doll Yuri made for her.-]
* BabyTalk: In all media, it depends on the translator to which extent Hina's speech pattern will be adapted, or not at all.
* BlondeBrunetteRedhead: The brunette to redhead Sora and blonde Miu.
* CheerfulChild
* ChildrenAreInnocent
* GirlsLoveStuffedAnimals: Keeps with her a bunny plushie Yuri made for her.
* LockedOutOfTheLoop: Concerning her parents' disappearance. Yuuta, Sora and Miu are trying their best to keep her cheerful until the time comes when she is emotionally stable enough to learn of the bitter truth.
* MoralityPet: To Yuuta's relatives -- her disarming cheerfulness and sunny disposition is one of the few reasons Yuuta is still the girls' guardian despite lacking legal rights over them.
* RapunzelHair
* StrongFamilyResemblance: To Yuri, which Yuuta instantly notices in all adaptations.
* ThirdPersonPerson: typical of anime characters her age.
* TokenMiniMoe

[[folder:Takanashi and Segawa Family]]
!!Yuri Segawa/Takanashi
-->Voiced by: Creator/SayakaOhara

[-Yuuta’s older sister, Shingo’s wife and biological mother of Hina. Yuri took care of Yuuta by herself ever since their parents died, despite great disapproval from her family, with only their aunt Yoshiko willing enough to give her a chance. During her high school days Yuri was famous as a sociable girl and a track-and-field star, lively to her peers yet composed to her seniors. Yuri met Shingo over five years ago, and they have grown so close to each other (and Yuri becoming a beloved stepmother figure for Sora and Miu) they eventually married (and bore a daughter, Hina), despite Yuuta's objections, resulting in him moving away as his way of conceding to the marriage. Despite this, she still keeps contact with him through phone calls and the occasional visit. One day she asks Yuuta to take care of her daughters for a week while she and Shingo are on vacation...only for them to suddenly disappear a week later.-]
* TheAce
* AdaptationDyeJob: Same deal as Yuuta, Yuri's blue hair is to represent black, some adaptations drop the stylish choice for ''real'' black hair.
* AdoptivePeerParent: By default, as the adoptive mother to Sora and Miu.
* CoolBigSis
* CosplayOtakuGirl: Is one, and insists to her daughters to keep it a secret from Yuuta. If he ever found out, she would have to "kill him" or force him to join her hobby. [[spoiler: Her extensive collection ends up being used by Sora four years later, making this a posthumous instance of PassingTheTorch.]]
* HairColorDissonance: Same as her brother, blue outlines for black hair.
* LethalChef: Yuuta once made an offhand comment about how, when they were still living together, Yuri was terrible at cooking, and even wondered when she started improving.
* MissingMom: [[spoiler: The 2nd OVA, where she and Shingo visit as ghosts, makes it quite clear they have been KilledOffForReal.]]
* PromotionToParent: Happens to her when she ends up taking care of Yuuta so that they wouldn't be separated by their relatives. This also occurs when she marries Shingo, who already has two daughters.
* YouGottaHaveBlueHair: Her default portrayal, still it is supposed to be black, the blue tint is just an artistic choice.
* YouNeedToGetLaid: In the novels, whenever they make contact, Yuri would suggest Yuuta to get a girlfriend "every two or three sentences". She also gets delighted when believing that Yuuta has one (or rather, Kouichi) cooking for him while they were talking on the phone.

!!Shingo Takanashi
-->Voiced by: Creator/NobuoTobita

[-Yuri’s husband and Sora, Miu and Hina's father. Despite hailing from a wealthy family, Shingo is a genuinely kind man, which attracted three different women, though the first two disappeared from his life for reasons not his fault: his first wife, Sora's mother, died way too soon; while his second, Sasha, Miu's mother, had a lifestyle radically different from his, which ultimately proved detrimental to their relationship. His marriage to Yuri, Hina's mother, brought back the joy he had with his first marriage. Shingo loves taking pictures of his wife and daughters, matching perfectly with Yuri's love for cosplaying which she passed to her daughters. One day they decided to travel abroad while leaving their daughters to Yuuta's care...only for their plane to disappear somewhere in Africa.-]
* CameraFiend
* DependingOnTheWriter: His importance and character presence, it varies depending on the medium; in the main manga adaptation, Shingo is just a throw-in, in the beginning he is not even referred by name, just "the husband". The anime and spin-offs are more generous to Shingo.
* DisappearedDad: [[spoiler: The 2nd OVA makes it abundantly clear he and Yuri were KilledOffForReal.]]
* EyesAlwaysShut: He does open them from time to time, though.
* HappilyMarried: Thrice.
* HenpeckedHusband: The novels seem to indicate that Yuri always has the final word in the household's affairs.
* {{Megane}}
* NiceGuy
* OverprotectiveDad: [[spoiler: Even comes down to visit as a ghost in the OVA special packaged with volume 18 of the LN, though he ultimately approves of Yuuta's guardianship and even his betrothal to Sora, making him very much a ReasonableAuthorityFigure.]]

!!Yoshiko Sawara

[-Yuuta and Yuri's paternal aunt and family representative for the latter during her and Shingo's "funeral". Yoshiko acts as a mediator. When Yuuta and Yuri's parents died she offered Yuri to have Yuuta taken care of by their relatives, but she stubbornly insists on raising him by herself. Despite her misgivings, Yoshiko gives her a chance, and to her surprise, Yuri actually succeeds in raising Yuuta into a fine young man. She would reappear again, this time to deal with Yuri and Shingo's daughters, now in the custody of Yuuta. Like what she did to Yuri years ago, she questions Yuuta's insistence to take care of his nieces by himself, but like last time, she eventually relents and gives him a chance to prove himself as good a parental surrogate as his sister had been to him.-]
* CoolAunt: Yoshiko eventually becomes a regular at Yuuta's dorm, not for inspection, but as a family member.
* ParentalSubstitute: it's revealed that Yoshiko was supposed to be the true legal guardian of Yuuta and Yuri after their parents' deaths, but she feels that she isn't ready to rear the siblings back then because she, too, has lost a loved one, her husband, not too long ago. By a twist of fate, Volume 1 of the novel ends with things repeating itself, although this time she embraces the role as Yuuta's and the Takanashi siblings' guardian, which she promises to relinquish to Yuuta once he comes of age at twenty.
* ReasonableAuthorityFigure
* WhatTheHellHero: Calls out Yuuta for running off with the sisters without the consent of the Takanashis. In the anime, when Yuuta tells her that he plans to quit college if it's for their sake, she also adds that, wherever she is, Yuri will not be happy at what he's doing.
** When she meets Yuuta's college friends, she instantly delivers one to Shuntarou upon learning that he was a floater.
* YouRemindMeOfX: Yoshiko's thought on Yuuta taking his nieces to live with him, it reminds her of Yuri taking little Yuuta for herself.

!!Sasha Irinichina Gagarina

[-Miu’s biological mother and a former Russian supermodel. Sasha started her career at fourteen, with a fluency in Japanese and Russian, though she became more well-known in Japan. She is also the subject of many a scandal involving her many dalliances, one of which was with a Japanese man who simply walked out on her and their lovechild -- Miu -- without even giving his name. Shingo, who became her friend through work, married her in order to give Miu a father and Sora a mother...only for Sasha to leave his and three-year-old Miu's side to look after her own mother following a family crisis, but not before forging a peaceful divorce so he could find happiness with her best friend, Yuri Segawa. They agree to let Miu choose with whom to live after grade-school, but when she returns to Japan seven years later, Yuri and Shingo have disappeared, and Miu barely remembers her. She then checks up on Yuri's younger brother Yuuta, testing his worth as a father-figure to Miu. Now a fashion designer, Sasha became a much more mature and responsible woman.-]
* ChekhovsGunman: in the novels, Yuuta first caught a glimpse of her while leafing through the Takanashi photo album.
* TheFashionista: She eventually becomes a fashion designer herself.
* GenerationXerox: Miu's high-class facade and preference for older men didn't come out of nowhere.
* IWantMyBelovedToBeHappy: Happy to grant Shingo a divorce so he can marry her best friend Yuri.
* PhenotypeStereotype: Blond hair and blue eyes, dictated for a Russian.
* SecretTestOfCharacter: Sasha assumed her past vain personality to see if Yuuta was truly qualified to be Miu's father.
* ShipperOnDeck: She found Yuuta to be such a caring person, that she wishes for him and Miu to marry as soon her daughter reaches legal age.
* SpellMyNameWithAnS: The ''Iriīnichina'' has some disputed translations, the '''ā''' in Sāsha as well, literally it could be written as Saasha.
* TheTease: When she arrives at Hachionji and met Yuuta, she threw herself at him in the pretense that Miu mustn't live without a mother-figure.

!!Nobuyoshi Takanashi

[-Shingo’s paternal uncle; Nobuyoshi Takanashi was the family representative for the “deceased” father at the funeral. Unlike Yoshiko, Nobuyoshi is the much more antagonist uncle of the family, he carries Shingo’s past relationships as his own failures, the fact that Shingo couldn’t find a suitable woman smeared dirt at the Takanashis in his eyes, Sasha in particular almost put the family’s name into shame according to Nobuyoshi, Shingo couldn’t have a more disgraceful woman than her, ironically sharing the same opinion Yuuta had in regard of Yuri’s marriage, Sasha already had a baggage with her. These traits places Nobuyoshi as a very uptight and distrustful man, he actually is the one who started the whole custodianship discussion, not caring about the sisters’ wishes at all, when Yuuta stepped in his discussion and dared to say he would raise all three of them by himself, Nobuyoshi immediately saw another problematic person interfering with the Takanashis. Now Nobuyoshi refuses to help Yuuta in any form, first by not letting him live in that big house the girls lived in, it belongs to the Takanashis, and not accepting Yuuta as a legitimate guardian for the girls, as of now he is okay with just a short agreement, nothing permanent.-]
'''Tropes applied to Nobuyoshi:'''


[[folder:Street Observation Research Society]]
!!Raika Oda
-->Voiced by:Creator/YuiHorie

[-A twenty-year-old second-year college student, liberal arts major, and member of the Street Observation Research Society. Despite her sharp mind and athletic talent, as well as a shapely figure (and large breasts), Raika's strange thought processes and offhanded attitude to her looks isn't winning her friends, more so once she starts dressing up in various cosplay outfits in public during her club activities. While initially coming off as somehow cold, she shows a lot of concern for her friends in her own unusual way. She also has a thing for cute things, such as the nieces of Yuuta, for whom she has ambiguously romantic feelings.-]
* TheAce
* AdaptationDyeJob: Raika's dark blue outlines on her hair, became somewhat purple in the anime.
* BadBadActing
* BerserkButton: Unlike Shuntarou, Raika believes that all three sisters are adorable, so every time he insults Sora, directly or not... *THWACK*
* BunnyEarsLawyer
* ClingyJealousGirl: In ''Rojou Kansatsu Kenkyuu Nisshi'', she doesn't react kindly to Nimura imagining that Yuuta was missing club activities because he finally found a girlfriend. Then again, this is [[{{Cloudcuckoolander}} Raika]]; it's hard to understand anything about her.
* {{Cloudcuckoolander}}
* TheComicallySerious
* CoolBigSis: To Yuuta and his new family.
* CutenessProximity: Triggered usually by Yuuta's nieces, Hina in particular.
* EarlyBirdCameo: in the manga, she was first seen through a bunch of pictures that Yuuta and Nimura were leafing through.
* EvenTheGirlsWantHer
* FriendToAllChildren
* GagBoobs
* HairColorDissonance: There are dark blue outlines for her black hair, in the light novels. It's not consistent, though; illustrations found in the same book may have Raika as a full brunette.
* ImTakingHerHomeWithMe: Unabashedly asks Yuuta about taking all three girls in.
* InnocentFanserviceGirl: None of them are intentional, even her cosplaying tendencies weren't meant for this, in her mind at least.
* LoveInterest: for Yuuta.
* MsFanservice: The greatest source of {{Fanservice}} in the series.
* PaperFanOfDoom: Her WeaponOfChoice whenever Shuntaro gets out of line.
* RedEyesTakeWarning: A subversion.
* SugarAndIceGirl
* UnknownRival: An AlphaBitch in Tama University (and manager of the men's American football team) sees her as this after beating her in last year's school pageant without so much as batting an eye on her.
* VictoriasSecretCompartment: once again, in the manga. Its contents include her ''fan'' of all things.
* WhenSheSmiles: [[ Nothing is cuter than a woman who is kind to children.]]

!!Kouichi Nimura
-->Voiced by: Creator/DaisukeOno

[-A nineteen-year-old college freshman at Tama University and Yuuta's fellow literature major and clubmate at the Street Observation Research Society. An outgoing young man who is also incredibly handsome and popular, Kouichi is a true ladies' man, attracting so many women to him yet having an innate kindness that keeps women close to him even long after they officially part ways. He's also a freeloader at Yuuta's place, claiming he only goes to his own home every time he brings women with him, though he repays for it by cooking for him and sharing expenses.-]
* {{Bishonen}}
* BishieSparkle: Happens to him quite a bit in the manga adaptations.
* TheCharmer
* ChickMagnet
* ChivalrousPervert
* CoolUncle: Becomes a surrogate version of this to the Takanashi sisters.
* EarlyBirdCameo: appears ''right next to'' Yuuta during a party at the beginning of Episode 1, and yet they only introduce themselves to each other until later. (Yuuta even points this out)
* {{Expy}}: Quite an explicit one of [[LightNovel/HaruhiSuzumiya Itsuki Koizumi]], from identical appearance, hairstyle, supernatural ability to charm the skirt off any girl and even sharing [[Creator/DaisukeOno the same voice actor]], except Kouichi uses the agressive-masculine "ore" when referring to himself instead of Itsuki's gentle-masucline "Boku".
* [[PrettyFreeloaders Handsome Freeloader]]: Claims he only goes to his own home if he has a girl in tow.
** Volume 2 inverts the situation. Yuuta is now living in the sisters' original home, and since he has to go back to Hachioji for college, he has to temporarily return to his apartment, which is now rented out by Kouichi (after he somehow [[NoodleIncident got expelled from his own dorm for undisclosed reasons]]), meaning that Yuuta is now freeloading off Nimura. The irony is not lost between the two.
* HandsomeLech
* InsistentTerminology: He doesn't trick girls to going out with him, he "invites" them.
* ItAmusedMe: in ''Rojou Kansatsu Kenkyuu Nisshi'', the way he describes Yuuta's association with Raika (even though he figured out Sora's feelings for Yuuta) to Sora, plus the facial expressions he makes, certainly would count. When Raika chances upon Yuuta and Sora in a "NotWhatItLooksLike" moment, he even quips that it's "going to become more interesting".
* MistakenForGay: Upon first seeing him in ''Miu-sama no Iu Toori'', Miu mistook him as Yuuta's lover.
* NeverLiveItDown: in-universe (novels), the Takanashi sisters never lets him forget the fact that he once tried (or at least jested about) hitting on them.
* NiceGuy: Womanizing tendencies aside, Kouichi is a do-gooder who treats his women with respect, repays others' kindness, and has since become a godfather-figure for Yuuta's nieces.
* NoodleIncident: After getting on the blacklist of a lot of people (highly suspected that he had "one too many") he has taken up permanent residence in Yuuta's dorm because his old one isn't safe anymore. May or may not involve his habit of bringing girls into his dorm.
* PedoHunt: before he got the whole picture, he thought of doing this to Yuuta when he first saw the latter with the Takanashi sisters.
* ReallyGetsAround

!!Shuntarou Sako
-->Voiced by: Creator/JunjiMajima

[-A third-year literature major at Tama University (whose age remains ambiguous due to being a floater, already in his third-year when Raika first entered) and founder-president of the Street Observation Research Society. Shuntarou is the image of a stereotypical otaku -- fat, wears glasses, and obsesses over girls. Naturally, his attraction for younger girls earned him a reputation for pedophilia, one he doesn't mind in particular. Despite all these, when the chips are down Shuntarou proves himself to be a reliable friend, especially now that Yuuta has to take care of his nieces in their missing parents' stead.-]
* AdaptationalAttractiveness: Inverted -- his appearance in the anime and manga spinoffs is less charming than his original novel design.
* AlliterativeName
* AwesomenessByAnalysis: Was able to accurately draw and guess Miu's and Hina's appearances just by talking to them on separate occasions on the phone.
* BeCarefulWhatYouWishFor: tells Raika that if she has to hit him, she has to use a fan instead of a shoe; this is ''after'' Raika already struck him down, so Raika proceeds to hit him ''again''.
* {{Blackmail}}: his recruitment MO. In Yuuta's case it's more of a roleplay, but with Nimura, well...
* BigFun
* BokeAndTsukkomiRoutine: intentionally invoked, with him trying to enforce this role with Raika. Unfortunately for him, Raika takes it ''too'' seriously.
* ButtMonkey: which can sometimes be taken literally, since Raika's usual punishment for him involves using her fan to [[LiteralAssKicking repeatedly slap him in the rear]].
** If Shuntarou would actually be in a novel's illustration, some misfortune always falls on him (beaten up by Raika, locked outside the house while everyone is partying inside, etc.).
* CameraFiend
* {{Cloudcuckoolander}}
* ClubPresident
* DiggingYourselfDeeper: Shuntarou is forbidden to enter the Takanashi residence unless Yuuta is home. This exchange happens:
-->'''Nimura''': "If incidents like one of Miu-chan’s panties getting missing after he goes home occur, the members of Roary would definitely be forbidden to visit.”
-->'''Shuntarou''': "The development of being judged to be guilty when a crime has yet to be committed should not be allowed in a nomocratic country where a jury system is starting to be used.”
-->'''Nimura''': "Has ''yet'' to be?"
* {{Expy}}: He looks a bit like [[Manga/HighschoolOfTheDead Kohta Hirano]] in the anime.
* HypocriticalHumor: one of Yuuta's neighbors detests Shuntarou with a passion, even though they're both {{lolicon|AndShotacon}} otakus that practically look alike.
* ImTakingHerHomeWithMe: a whole lot creepier than Raika at this, even ''before'' you consider his gender.
* LargeHam
* LoveFreak: "Love is justice, Love is the strongest". Said by the man himself.
* LovableSexManiac: With a mild whiff of being a paedophile.
* MemeticMolester: in-universe, Yuuta firmly believes he's not one to be associated with when you've got young girls living together with you.
* MyFriendsAndZoidberg: whenever Yuuta thinks about the SOS Club, Shuntarou's name is always an afterthought.
* OpaqueLenses: or skin-tone lenses, as seen in some light novel illustrations.
* OtakuSurrogate
* PassingTheTorch: hasn't happened yet, but he's apparently grooming Yuuta to be the club's next president.