Timetraveler Rui Kamishiro

Tsukasa Tenma is the prince of the White Lily Kingdom, the future heir and the favorite of the entire kingdom. He is kind and responsible, always ready to help everyone in need. His life was peaceful and calm, until one moment...

Walking through the garden, Tsukasa suddenly came across... A man?! The stranger was lying unconscious in the bushes, his clothes were very strange, and in his hands, it seemed, was a mysterious artifact... The prince could not understand what it was, and he had never seen such clothes even in other countries.

After about a minute, the man opened his eyes and sat up, yawning. He stretched and looked around quite calmly, also examining Tsukasa.

Hmm... Maybe... Around the eighteenth century... I was thrown quite far away...

The stranger takes a notebook out of his pocket and starts writing something.

Oh, yes, sorry for the intrusion. I am Kamishiro Rui, let's get acquainted. Don't pay attention to me...

But how can he not pay attention to him?!