Lone: The Wanderer - Chapter 43Book 1: : Agreement and Intoxication

Beautiful doctor of Chinese medicine, Yu Gangan woke up from a coma one day to a cold, mysterious man. “Excuse me, you are…?”

A pair of profound eyes focused on her and replied, “Fang Zhihan, your husband.”

Did this man take her for a fool? He was obviously a fraud!

A little while down the track, he pulled her into his arms and whispered beside her ear, “Who am I?”

This time, Yu Gangan froze and replied, “Fang Zhihan, my husband.”

If he was a patient, then she was his sweetest medicine…

- Description from Novelupdates

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.