During his high school days Sung-Hyun was confirmed as an Omega, and his relationship with four alphas who were his friends was cut off. He thought that they would never meet each other again, but he found himself reunited with them again one day.

That fateful day, Sung-Hyun was surrounded by the four Alpha's and no matter how many inhibitors he took, he went into heat...

(Source: Lezhin, translated)

Note: Chapter count includes two extras.