Shinonome Hajime spent his childhood in the slums, fighting tooth and nail to become strong in order to survive. Now, he lives calm and comfortable days as an adventurer living in Komai Village. One day, while carrying out a mission in a dungeon, he finds a girl who was almost eaten by a Slime, the weakest monster! The girl’s name is Lilui. He entered the dungeon alone to survive. Since Lilui had been abandoned by her parents and had nowhere to go, Hajime couldn’t just abandon her. He took Lilui back to the village and started living together! The days together for the two of them began.