Kyoudai hodo Chikaku Tooimono wa Nai

Ane (older sister) is uber perfect; she's beautiful, intelligent and is admired as the president of the student council. But, when it comes to her little brother, she goes nuts, unable to control her over-the-top obsession with him. Their days get even more chaotic surrounded by a bunch of oddballs, from a mentally-disturbed best friend, their little sister with a sister complex, an ex-punk convenience store manager, a hardcore masochist, a loli-con and more! Casual comedy perfect for filling your spare time.

(Source: Manga Box)

Kyoudai hodo Chikaku Tooimono wa Nai was simultaneously published in Japanese, Chinese and English (as I'm Obsessed With My Little Bro!) on DeNA's Manga Box app, though English translation was halted after 31 chapters.