|Volume||Light Novel Volume 4|
Sisters is chapter 46 of the Boku wa Tomodachi ga Sukunai light novel series. It is chapter nine of volume four.
A day after their finals ended, Maria comes to Kodaka's house just as he is cooking their dinner and explains to him that she ran away from her home, much to Kodaka and Kobato's surprise. By then, Kate, the older sister of Maria, calls, telling Kodaka to take care of Maria as she stays at their house but Kate also gives him the option of bringing Maria back to their house. After Kodaka agrees to let Maria stay, Kate hangs up the phone.
Afterward, Kodaka, Kobato, and Maria had dinner, which ends with a competition between the two girls. As they were, Kate calls as Kodaka informs her that they are currently having dinner and Kate advises Kodaka to tell Maria to eat her vegetables. After hanging up, Kodaka finds their dinner table completely gone with food as Kobato and Maria point at each other after Kodaka asks who is responsible.
Later, as Kodaka washes the dishes and Maria following her, Kate calls again and Kodaka informs her that Maria ate all her vegetables before hanging up again. Afterward, Kobato asks her brother to play a video game with her but instead lets Maria take his place. After taking a bath, Kodaka calls out to both Kobato and Maria for their turn taking a bath. Maria bathes first and Kodaka informs Kate as she calls that Maria is currently in the bath. As Kodaka and Kobato play, Maria comes out the bathroom, naked, and complains as the pajamas provided to him by Kodaka is tight on her chest, causing Kobato to yell at the latter to not sleep. With no other clothes to wear, Kodaka provides Maria with his t-shirt and Maria happily accepts.
After hours of video gaming, Maria finally falls asleep, followed by Kobato as she goes to her room. After laying Maria down on a futon, Kate calls again and tells Kodaka to have him brush Maria's teeth. Kodaka then asks Kate if she has sister complex, causing Kate to yell in response at Kodaka through the phone and hang up. After brushing Maria's teeth, Kate calls numerous times until Kodaka is able to unplug their phone.
The next morning, Maria decides to head back to her home with Kate coming to pick her up. After apologizing for being a bother, Maria asks Kodaka if she can come again next time. As Kodaka agrees, Kobato yells at Maria to not come back as Maria yells back at her in return. When the Takayama sisters left, Kodaka finds Kobato playing her video game as training for when the next time Maria visits their house, much to Kodaka's amusement.