Saikin, Imouto no Yousu ga Chotto Okashiinda ga: Grrr!

A close-up of Shoutarou Torii and Moa Torii baring their teeth at one another from opposite sides

Shoutarou Torii and his little sister, Moa, do not get along. He finds her rude and mean most of the time, especially when she calls him “baldy”, while she considers him to be loud, annoying, and shamelessly perverted. That said, he won’t hesitate to protect her if she’s in trouble.
From the anime series Saikin, Imouto no Yousu ga Chotto Okashiinda ga. (Recently, My Sister is Unusual)


Mitsudomoe: Spoiled Brats

A close-up of Miku Sugisaki grabbing Ryuuta Sugisaki by the cheek

Rich kid Miku Sugisaki is haughty and loves to brag about her expensive clothes and possessions, while her younger brother, Ryuuta, is ill-mannered and selfish. That said, she does try to make sure he stays away from bad influences.
From the anime series Mitsudomoe

Tsugumomo: Overactive Imagination

A blushing Kasumi Kagami, garbed in a white shirt andd pink apron, holds herself and acts surprised. Kazuya Kagami looks at her, unamused, in a red T-shirt and blue shorts.

With their father always working and their mother having passed away, Kasumi Kagami assumed the responsibility of taking care of her younger brother, Kazuya. She can be a bit obsessive when it comes to his safety and well-being, though. (And from his perspective, the less said about her desire to tend to his physical needs, the better.)
From the anime series Tsugumomo