Thirteen-year-old Kouta is just an ordinary middle school student living an average life; lusting after the school idol, playing video games during his free time, and having a workaholic father. One day, his father announces that they'll transfer to Sapporo, leaving him alone while his father takes care of the papers for their move. On that day, he meets a young woman, a high school student, volunteering to take care of him.
The girl, Natsuki, then proceeds to live with Kouta, taking care of him while making things awkward with her eccentricities... So begins Kouta's new life with a girl four years older than he is.
Ane Doki provides examples of:
- Accidental Kiss: Happens between Kouta and Chia in a restaurant.
- A-Cup Angst: Kanade, after meeting Natsuki.
- Big Bad: Natsuki's older sister, Haru. For a few chapters, anyway.
- Book-Ends: The manga begins and ends with Kouta meeting up with Natsuki with ice cream.
- Boy Meets Girl
- Clingy Jealous Girl: Kanade
- Cut Short
- Dude, She's Like, in a Coma!: When Kouta passes out from lack of sleep, Kanade gets mistaken for doing this.
- Girlish Pigtails: Kanade
- Jerkass: Haru, again. Not only she's trying to force Natsuki to get married with a rich old man so his money can help her company to keep successful,she goes as far as kidnapping Kouta to convince Natsuki to come back home. This quickly changes.
- Important Haircut: Kanade, after the fire works festival.
- Indirect Kiss: Brought up by Kouta when Natsuki takes his ice cream and eats it.Kouta: This means that this hot girl and I just shared and indirect kiss?
- I Want My Beloved to Be Happy: Played straight with Kanade at the end. Also Kouta keeping his feelings about not wanting to move in last chapters to himself so as to not trouble his father.
- Meido: What Natsuki considers herself while staying with Kouta. She even at one point dons a Maid cosplay outfit at one point.
- Marshmallow Hell: Poor Kouta
- Ms. Fanservice: Natsuki, oh so much.
- Chia gets a few moments like this as well.
- Missing Mom: Kouta's mom never figures into the story.
- Nose Bleed
- Ordinary Middle School Student: Kouta.
- Panty Shot: On a regular basis, usually from Natsuki.
- Pervert Dad: Kouta's father spends almost all of his earnings (and sometimes even his company's money) on strip clubs.
- Rescue Romance: Kanade falls for Kouta when he (and Natsuki) rescues her from the group of gangsters.
- Tsundere: Kanade
- School Idol: Kanade Sakurai.
- Shipper on Deck: Natsuki seems to be one for Kouta and Kanada.