Saigo no Ω wa Tsugai ni Narenai  

The Last Omega Cant Be "Tsugai", Saigo no Omega wa Tsugai ni Narenai, 最後のΩは番になれない

The virus that spread throughout the world only affected Omegas. Out of all the Omegas, there was just one survivor - Shuu Miyamoto, an Omega with natural immunity to the virus. He was then isolated by a government research institution and forced to reproduce with Alphas. However, Honda, the Alpha chosen for reproduction, had a unique trait in that he caused Shuu to go into heat when their eyes met. Despite knowing that they were fated partners, their relationship could not be eternal due to circumstances beyond their control.