Travel Through and Rule Another Universe

On the way home by bus, the male protagonist was attacked by an outsider and fell into a sewer manhole cover. It turned out that the sewer manhole cover was the crossing point. When he traveled to another world, he met a thief and stumbled along the way. Finally, he became powerful and founded his own country. Then many things happened. In this way, he founded his own country, and through unremitting efforts, he unified the universe. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.