Namaiki na Gal Ane wo Wakaraseru Hanashi
生意気なギャル姉を解らせる話
The Day I Decided to Make My Cheeky Gyaru Sister Understand in My Own Way
Namaiki na Gal Ane wo Ore no Houhou de Wakaraseru Koto ni Shita Hi· 生意気なギャル姉を俺の方法で解らせることにした日
manga
This is the story of a brother who's very concerned for his little sister who's turned into a Gyaru and rebels against him, because of that he's chosen to make her "understand" in his own way.