Ukei Kaito, the protagonist who desperately saved the world after being summoned in another world as a hero to defeat the Demon Lord. Though he did defeat the demon lord and saved the world, but he was betrayed by the people he trusted as friends and is stabbed to death by a sword. At that time, he swore. If there is a next time, he would no longer cling to the word called 'believe'. If there is a next time, he would pay them back as cruelly as possible. If there is a next time, he wouldn't make another mistake. 「I... All of you... I will absolutely kill you all......」 After leaving his last words, he died. And then a voice resounded. .........【 System Message: Tutorial Mode has ended. 】.