Sayonara Bye Bye
Prequel http://www.mangago.me/read-manga/hajimari_wa_sayonara/ Gives a better context of Rei and Yuto.
Baby, Sugar, Succubus
Summary Arata, a café owner, meets a university student, Shinya, who, despite being male, is a succubus with a pure heart!
Uchi no Koakuma-kun
Summary Spica, a little demon who yearns to become a succubus, and so he breaks the law to travel to the human world alone. There he finds a human male to attack. He tries to steal his energy by having sex but the human thinks the whole situation... is just a dream?!
Inma na Osananajimi ni Furimawasarete Imasu
Itoshino Inma wa Banken Wanko ga Dokusen Shimasu
Summary Shiki Sakihara , a 3rd year high school student for some reason gets too much attentions from other guys ..his only silver lining being Atsuya , his only male friend, an underclassman who saves him from sticky situations .which earned him the name guard dog among his peers ..But when Shiki learns that Atsuya has feelings for someone else Shiki was dumbstruck , he felt strange emotions he couldn't understand ..& soon he started emitted denser pheromones & cross the line ..soon enough he founds out that he is a half - succubus
Hajimari Wa Sayonara