One holiday, the protagonist, whose creed in life was "enjoy yourself", but who also had traumatic experiences with both romance and women, was once again being chided by his childhood friend, Hikari, for not trying to get a girlfriend.
She was worried that if this continued then he would become a failure of a human being. But he just wanted to spend his time enjoying his hobbies and ran away from relationships by any means necessary.

However, a wrench would get thrown into his plans when suddenly a bright light enveloped them both and they were transported to another world. When they opened their eyes, they were looking at a major port city. While they were still baffled by their new surroundings, a woman, who identified herself as the Prime Minister of the town, told him that he was the "last king" of the kingdom.

Not taking no for an answer, the people forced the position of king onto the protagonist. Moreover, the first romance of his life was to come about as a result of his kingly duty to "build a harem, father heirs, and stimulate the growth of the kingdom."

He was forced to have a harem. In fact, it had already been arranged that the princess from the neighboring kingdom, Sophia, and Charlone, the beautiful daughter of a noble family, would be part of this harem. Day by day, more and more beautiful girls ended up surrounding the protagonist, much to his dismay. Seeing him surrounded by girls, Hikari began to fear she might lose him.

"I just want a normal romance!"

And so the curtain draws on the tale of our protagonist's chaotic harem romance!

[From Hau~ Omochikaeri~! and Official Summary]