Sekai Heiwa wa Ikka Danran no Atoni

is a Japanese light novel series written by Kazuya Hashimoto, with illustrations by Koban Sameda. The series began publication on February 10, 2007 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
There used to be a battle. A battle between the demons led by the Demon King who claims to win the world and those who are oppressed by it. Among them, humans use their own magical power to summon "heroes" from another world. The hero sets out to subdue the Demon King with the summoned princess of the nation, and finally destroys the Demon King. However, at this time, the Demon King transferred the hero and the princess from the world in which he was to another world, which is not known as Doko, and attempted a trade-off. As a result, the hero and the princess will be sent to a world far from the world they have been adventuring, as the Demon King intended. That is, to modern Japan, which was the homeland of the brave man.

Decades have passed since then.

A hero and a princess's family, the star bow family, who have a strong family in modern Japan. The brothers and sisters born there all have special powers that ordinary people cannot have. And they were born under a star that had to be resolved inevitably when they were involved in a world crisis. In such days, the eldest son, Hito, faces three crises that attack himself, the world, and his family at the same time.

This is a funny and warm story woven by a family that protects world peace. It is a story of a small struggle to protect the "family", which is the smallest unit in the world, of the eldest son, who can be said to be the weakest in the family, to protect the peace of the family to protect the world peace.