MTL - Wonderful Life After Exchanging Fate - Chapter 40

Yamagata Tatsumi and his family were traveling in their car when a wild truck smashed into their car. But wait! The MC wasn’t dead yet, his entire family was though. With his entire family dead and relatives abandoning him, the only one remaining by his side was his pet cockatiel. For a year he lived only with his pet, who had been with him since childhood. But finally, her lifespan reached its end and she died in his arms.

As part of the imperial family, every move by Chu Yuan in this game of chess is made with apprehension, fearing that with a moment of inattentiveness, the whole match will be lost in a single move. Ascending to the throne at eighteen, not half a year passes before civil strife erupts in Yun Nan. Though the thoughts of the old guard at the imperial court are not exactly identical, they are all waiting to see how the new emperor will put an end to this. Unexpectedly, before this side could make a move, a few thousand miles away, the King of Xi Nan, Duan Bai Yue, had already personally commanded troops to attack in all directions; not half a year had passed when peace was restored. Sparse moonlight shines into the palace; Chu Yuan stamped the wax seal himself, and had a secret letter sent urgently to Yun Nan 800 miles away — this time, what must we(1) give in exchange? Brush marks passed through the back of the paper; it almost can be seen, when writing this line, how angry the young emperor was. Duan Bai Yue spread out a piece of paper unhurriedly, replying with only one word. You.

This is the story of a boy who lived a secluded life in the mountains, tending his farm, rearing his fish, and dreaming his dreams. Eh? Did I suddenly conquer all worlds and become the big boss? Or am I still in a dream?

- Description from Novelupdates

God plucked one of his creations from his first Earth and gave him a second chance in another one of his Earths...surprise it is in DxD! Now reincarnated as a perverted side character how will our poor protagonist handle his new identity? Well he probably wont make the choices you will want him to, that's for sure!