Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ - Volume 10 Chapter 4

The 7-year-old little crybaby met 11-year-old big brother who ran away from home.
[This man became the protector of redemption in his life]

The 16-year-old little dragon fell in love with a 20-year-old big brother.
[It’s a pity that the big brother didn’t recognize him as the little crybaby]

The 23-year-old single father and 27-year-old chief executive meets again.
[This time the little crybaby and his big brother are finally together]

Fortunately we met through hundreds of millions of people, Thank God, for letting us break through many obstacles and get back together again, falling in love with you and being with you again is the greatest fortune in my life.

- Description from Novelupdates

Hye lived his entire life without a class. After the apocalypse hit the human world, strange creatures invaded and killed humans while new lands were being added.

Systems were given to humans and with the help of the guides, humans started to fight back for their lives. All of this happened under the watch of the venerable beings who were shining stars in the sky; gods!

Hye dreamt his entire life of a chance to prove himself. He was a hard working, earnestly learning and smart youth. However, the apocalypse never was merciful to such humans at all.

Until one day he got a chance to go back in time, when everything started. At this new starting point, he found himself able to finally obtain what he wanted, a class for himself and power beyond imagination.

But will things be this easy for him?

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.