*“I won't become a hero even if I am poor, because as long as Honoka continues to smile, it's all worth it.”* Monsters are on the loose! But luckily for the people of Japan, heroes are there to protect them, with powers that run on a rate of yen per second. For Hiasa Sen, however, there are many more important things to worry about, like catching sales on groceries, and his many part-time jobs, all to take care of his little sister. When danger approaches, however, he has a secret power of his own, but it may be more trouble than it's worth. (Source: Comikey)

One day, Kaito Kuji, a high school student, got knocked out and lost all his memories. When he woke up, a gacha machine crank and a sign that says "Thank You" was attached to his chest. He can gain special powers and recollect some of his memories when someone utters those words to him and he turns the crank.

In this world, there are “hunters” who conquer “ruins” that have appeared from another world in search of treasure. The protagonist, a dropout named Kurogane Touma, risks his life to explore the extremely difficult ruins (dungeon) for his sick sister. There he encounters the most powerful sword and “Aion,” a supernatural being that feeds on love. The battle to save his sister and the world begins!