Siscon Onee-chan to Ki ni Shinai Imouto

Synopsis

There's no such thing as an older sister who hates their younger sister. Every older sister on the face of the Earth loves their younger sister dearly. I, Sakura Shima, have an adorable sister one year younger than me. The sister yuri comedy everybody is talking about!

(Source: Japanese Publisher, translated)

Note: This is the serialization of the webcomic originally self-published on Nicovideo.