Suki to Suki to de Sankaku Ren’ai [Japanese]

Description:

Ever since his father’s remarriage when he was a young child, he has lived with his stepsister Nanaru, while enjoying a happy otaku life with his childhood friend Maho and the rest of the otaku club. However, this everyday calmness was broken with the return of his real imouto Suzu one month before summer vacation. She was pretty much the perfect imouto, and it created an awkward relationship between Suzu and Nanaru. They both strived for his attention, appealing to him with their starkly different hobbies and personalities. As if that wasn’t enough of a problem, his senpai Shiina fell in love with him at first sight and forced her way into the club, causing Maho to start acting oddly as well. Caught up in two triangle relationships at the same time, what will happen to him!?

[From Hau~ Omochikaeri!]