The Demon Who Became My Sister
Tbh, this is one of the better one i've read. The "brother and sister" tag shouldn't really be there, since they aren't brother and sister by blood nor law. The little uke summons the demon ( AKA big sister ) and basically wants an older sister. But they kiss and are a little touchy touchy... But I gotta say, that demon girl can be my sister anytime. Do my hair and help me go through life as a woman, also wouldn't mind touching them boobs.
Isyuzoku Joshi ni ○○ Suru Hanashi
This is one of my fav Yuri! I love the whole monster girl idea, really gives a spark to the whole manga. The Main girl, (One with short black hair) Is a pev. However she is the one Human in an all monster school. She checks out the monster girls in many ways, (wink wink) I love the story and believe you should check it out.
Onibito no Matsuri Daiichiwa - Zurui Meguriai