Description:

Sui doesn't like her older sister's boyfriend, Midori-kun. She was annoyed by his attitude, always making fun of her and treating her like a child. But in the winter of her last year of junior high, her mom asked him to help tutor her for her high school entrance exam...? (Source: Betsuma, translated)

Alternative Titles:

お姉ちゃんの翠くん, Onee-chan no Midori-kun