Demi-chan wa Kataritai by Petosu — Ongoing

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Succubus, Dullahan and Vampire. They are known as Ajin, or "demi"s and are slightly different than the average human. They have lived alongside humans for ages under persecution. However, in recent years, they have become accepted as members of society. This manga follows a high school biology teacher who has a great interest in demis and his interaction with the various demis in his school, each with their own cute problems.

Volume 1
Chapter 1: Takahashi Tetsuo Wants To Communicate released Nov 24 '15
Chapter 2: Vampire-chan is in Adolescence released Nov 28 '15
Chapter 3: The Takanashi Sisters are Close released Dec 2 '15
Chapter 4: Dullahan-chan Wants Some Attention released Dec 8 '15
Chapter 5: Dullahan-Chan Is So Cute! released Dec 14 '15
Chapter 6: Succubus-san Likes to Dream released Dec 28 '15
Chapter 7: Takahashi Tetsuo Wants to Protect released Jan 31 '16
Chapter 8: Takanashi Hikari Wants to Talk released Feb 15 '16
Chapter 9: Demi-chan Wants a Hug released Feb 26 '16
Volume 2
Chapter 10: Succubus-san Is A Good Adult released Mar 7 '16
Chapter 11: Takanashi Himari is Doubtful released Mar 16 '16
Chapter 12: Yuki Onna-chan is Cold (Part 1) released Mar 25 '16
Chapter 13: Yuki Onna-chan is Cold (Part 2) released Apr 4 '16
Chapter 14: The Demi-chans are Friends released Apr 11 '16
Chapter 15: Demi-Chan Wants to Be Called released Apr 21 '16
Chapter 16: The boy is Kurt released May 3 '16
Chapter 16.5: Takanashi Hikari is a Vampire released May 12 '16
Volume 3
Chapter 17: Succubus-San is Confused released May 31 '16
Chapter 18: Adults are Awkward released Jun 17 '16
Chapter 19: Demi-chan Wants to Study released Jul 10 '16
Chapter 20: Demi-chan Wants to Bite released Jul 23 '16
Chapter 21: Lose your Temper, and You Lose More Than Just That released Aug 7 '16
Chapter 21.5: Succubus-San's Day Off released Sep 2 '16
Chapter 22: Succubus-San Takes Action released Sep 25 '16
Chapter 23: Demi-chan Doesn't Talk released Oct 15 '16
Volume 4
Chapter 24: The Sisters are Slobs released Nov 18 '16
Chapter 25: Dullahan Transcends Time and Space (Part 1) released Dec 22 '16
Chapter 26: Dullahan Transcends Time and Space (Part 2) released Jan 30 '17
Chapter 27: Even More Than Novels, In Fact released Aug 6 '17