the time between us

Karl Jacobs jumps through time for fun, exploring and finding new places everyday. One time jump, he comes across his country but with only a couple of houses there. It must have been the time where it was being built. Karl had never travelled back this far before.
Whilst exploring Karl meets a boy who introduces himself as Sapnap. Sapnap shows Karl around his and his friends country in the making. Karl is reluctant to his mess of life so he decides to stay in this time period with Sapnap who is completely unaware that Karl isn't meant to be here. But in doing so Karl and Sapnap manage to fall completely in love with each other. But Karl can't stay living in this time period forever. He will have to leave at some point. Right?