Yandere Imouto Ni Aisaresugite Kozukuri Kankin Seikatsu The Comic summary:

Ayane is in love with Tomoya, Her Onii-chan. But, their childhood friend, Sayaka is trying to split them up. Ayane is not going to let that happen, No one can take Onii-chan away from her. Her plan? She wants Onii-chan only for herself, and she is willing to do everything to make that happen. She wants to have a family with Onii-chan, only the two of them. No one else matters in her little world, and she is going to take care of everyone who tries to interfere.(https://twitter.com/gomzaburo)