Haruma Kawagoe has had the lifelong wish of being an older brother. However, after a miscarriage and an operation
, his mother could not give him a little sister. Nevertheless, he never gave up on his wish.
One Christmas night, during his college days, Haruma has a huge present delivered through his window by a woman on an airborne motorcycle claiming to be Santa Claus
. The present contains the little sister he always wanted, and Santa justifies the time it took to fulfil his wish by saying that making a little sister takes a lot more time than just making an android
manga and anime follows Haruma's life as he attempts to adjust to suddenly having a little sister out of the blue, especially a little sister who has an instruction manual with material inappropriate for her age, and follows it religiously.
Tropes this show has examples of:
- Accidental Pervert: Inverted in episode 4. Makoto pushes Chitose into Haruma's apartment. Poor Haruma, he was only wearing a towel.
- All Love Is Unrequited: Taken to almost absurd levels - literally every single character except Choco is in love with someone totally oblivious.
- Captain Ersatz: "Tirantano", "Cancent Villo", "Buffalo 99", to name a few.
- Childhood Marriage Promise: In the manga, Haruma made one to his cousin Konatsu.
- Christmas Episode
- Cloud Cuckoolander: Chitose has a rather vivid imagination
- Cosplay: Not so much in the series proper, but the below-mentioned dancing theme is obviously aimed at cosplayers—and not without success.
- Crouching Moron, Hidden Badass: Yasuoka, the lethargic unemployed neighbor at the protagonists' apartment building, is actually a former detective and aikido expert.
- Dancing Theme: Neko Nyan Dance, anyone?
- Defrosting Ice Queen: Yurika.
- Erotic Eating: Done by Choco with a chocolate-frosted banana
- Eyes Always Shut:
- Tamami, With one, blink and you'll miss it exception in episode 6 As pictured in this screencap◊, her one eye partially opens for a brief moment.
- Yasuoka as well, though less as noticable
- Extreme Doormat: Chitose.
- Fanservice: Quite a bit of it
- Fluffy Tamer: Choco, with Kuro the panther.
- Furo Scene
- Girl in a Box: specifically, a little sister delivered in a present. Oh, and it's a bag, not a box
- Done twice in the valentine's day episode with a box, the first time was all just a dream, the second, well, didn't end so well for poor Choco Haruma tapes the box shut and shoves it into a closet, much to Choco's dismay.
- The Glomp: Choco loves doing this to Yurika.
- Hadaka Apron: worn by Choco at one point because her manual says that older brothers love this sort of thing.
- Hard-Drinking Party Girl: Makoto, one of the tenants where Haruma is staying, who also loves to tease their landlord.
- Hot Springs Episode
- I See Dead People:Choco meets Yasuoka's deceased daughter and wife at the amusement park.
- In the manga's finale, Choco has a similar encounter with Kuro the panther and a woman revealed to be Yurika's mother.
- Landlady: Chitose
- Lovable Sex Maniac: Makoto, although she tends to go a bit far in her teasings at times.
- Meganekko: Chitose
- Manic Pixie Dream Girl: Choco proves that you needn't be a potential love interest to fulfill this role; Choco shows all the cheerfulness, innocence, and absolute devotion that defines a MPDG. Fortunately, she does not keep the original meaning of a zero-development plot device, but actually develops a great character of her own from this start.
- No Social Skills: Choco has no experiences in life at all, and relies entirely on her inappropriate manual.
- Ojou: Yurika. Her home is huge.
- Ordinary College Student
- Panty Shot: To the point of ruining a very emotional scene.
- Promotion to Parent: Choco's arrival forces Haruma into this. Luckily he gets a lot of help (?) from his neighbors.
- Put on a Bus: Ayano.
- RetGone:Choco, at the end of episode 22 and through most of episode 23, after Haruma insists to his cousin that he has no little sister.
- though nobody remembers Choco directly, her presence still existed in their unconscious memories, as well as other indirect evidence of her existence remained, which eventually clued Haruma to finally remember Choco
- Santa Claus: Well, a Santa, if not the actual old cheerful man.
- Sdrawkcab Name: Ashirai Makoto and Otokami Alisa.
- Shouldn't We Be in School Right Now?: One should worry for Choco's future, seeing as she never gets any education.
- Shout-Out: One of the last chapters features a picture of Yotsuba&!'s main character Yotsuba on a milk carton.
- Theme Tune Cameo: The ending theme, Neko Nyan Dance, is the Dancing Theme of an in-universe children's TV show. One episode centers around the apartment residents making a video of themselves performing the dance.
- Tsundere: Yurika, voiced by none other than Rie Kugimiya.
- Tsurime Eyes: Hideko, Yurika's maid, sports them.
- Not to mention Yurika and Makoto. Ayano's fiance also sports them
- Undead Tax Exemption: Choco's appearance somehow doesn't cause any problems.
- Why Do You Keep Changing Jobs?: Tamami.
- Zettai Ryouiki: Yurika.