Usuka Yukiichi, a student living a peaceful life in Japan, was suddenly caught up in a class summoning as a warrior from another world during a school break.

At that time, he heard a mysterious voice.

The otherworld country that summoned Yukiichi and his classmates asked them to gain power as warriors to face a world crisis, promising them preferential treatment including guaranteed living expenses.

However, thanks to a classmate's words, he was given the opportunity to consider his actions, so he left the castle to get a brief look at the world.

As a result, rather than accepting privileged treatment, he volunteered to become a soldier, aiming to build his own achievements and become an adventurer.