Suki Sugiru Kara Kanojo Ijou No, Imouto Toshite Aishite Kudasai summary:

Suki Sugiru Kara Kanojo Ijou no Imouto Toshite Aishite Kudasai manga, I love you too much so please love me more as a younger sister than her I was accepted to work at the game company that I admire SGO (Sister with Great Onii-chan)! The job given to myself, Keita Majima, a high school student who got such a miracle is "Rental Onii-chan" to make the best sister character! It's a sister-sister contract romantic comedy story full of affection between myself who loves younger sisters and the girls who want to be my younger sisters!