Demon Boys

MC is a down on his luck guy. He lost his money but stumbled across this invasive and crude demon! They’re assumed to have some sort of past that hasn’t quite been revealed yet.

There are 3 (I think) storylines in this toon and each one has a demon/devil significant other. The first story is really sweet and cute (reincarnation + stuff) the second one is more melancholic… I don’t know how to describe it - it’s about control and emotional abuse. The third one is bittersweet.

This young demon named Kouen has fallen for Higure, who once saved him and was so kind to him when he lost his way and wandered into the human world. On the day that Higure turned 18, thunder and lightning struck and Kouen descended in front of Higure. While he intended to act cool and tell Higure how he intended to take him as his wife, his plans end up turned upside down.

A college student Satoru Shiiyama had a crush on Jun Mariya ever since middle school, but the object of his affections dies in an accident. In the midst of his grieving, Satoru accidentally summons a demon and gets a once-in-a-lifetime offer: "In return for your life span, I'll grant you a wish." Having lost all hope, Satoru agrees. Just what is the wish that he made...?

I LOVE THIS ONE. I always come back to reread it!
A college student Satoru Shiiyama had a crush on Jun Mariya ever since middle school, but the object of his affections dies in an accident. In the midst of his grieving, Satoru accidentally summons a demon and gets a once-in-a-lifetime offer: "In return for your life span, I'll grant you a wish." Having lost all hope, Satoru agrees. Just what is the wish that he made...?

The door to hell can only be opened by authorized personnel, and Takimura has found he is one of them. The problem is, he's still alive! Every workday Takimura is greeted by none other than the King of Hell himself, Enma. And everyday he asks Takimura the same question: "Have you decided to become mine yet?"

In order to protect his people from attacking demons, Prince Val uses a demonic sword and curses himself in the process. He leaves his kingdom to find a cure, and his search leads him to Hallwil, the person rumored to be the only one who knows how to break the curse. Hallwil agrees to help Val... for a price.

A narcissistic apprentice devil suddenly appears before a lonely shut-in? In order to pass his final exam, Tougo Nishizaki, an apprentice devil, makes a contract with the shut-in college student Sugishita Masato. He’ll grant three of Masato’s wishes in exchange for his chastity and life energy. Another apprentice devil, Yoichi Murase, has a contract with Nishiima. His arrival brings the lives of these four together in a story you can’t take your eyes off of! A surprising happy ending.

In order to defeat the Demon King of Mano who was feared by the people, prince Ike embarked towards the castle alone. But, he was easily defeated by the retainers.
However, in order to defeat the Demon King and make a name for himself, Ike spends his days attacking the weak Demon King, who keeps running away.
On the contrary, he gets to know the Demon King who worries about him(Ike) and treasures plants. And before he knew it, he started to enjoy being with the Demon King...

While in pursuit of criminals, a police officer has an unexpected encounter with a rather uncanny demon. Barely surviving the incident, Do Gyeong Joon is left staring after the retreating form of the mysterious creature in bafflement. However, not long after this the two meet again when the demon crashes into Do Gyeong Joon’s apartment, saying: “Hurry up! I need to get inside of you”