Imouto wa Gal Kawaii

GAL sister can make anything come true
Shohei Shindo has a sister-in-law when his father remarries.
That little sister is Rino Mizusawa.
Her appearance was GAL itself with blonde hair, piercings, and a miniskirt.
Shohei, who has an otaku hobby, and Rino, who speaks the GAL language, should never have any contact, but they end up living under one roof as a family.
Even if Shohei sees Rino wearing only a bath towel, she doesn’t mind and treats Shohei as her brother and sister in a friendly manner.