Oozeki Eishi

Was I reborn into a mobile game!? Now that I can cheat with my phone to make unlimited in-app purchases and unlock infinite chests, I'm going to win this game!

A tired middle-aged man, Makoto (38, single) was attacked by thugs in a night park and died. Or so he thought, but when he woke up, he found himself in a dungeon in another world! Not only had his body become younger, but he also possessed the power of a spirit mage who could control black flames!! Glad for this opportunity, Makoto bid farewell to his terrible days in Japan and teamed up with Yuuka, a tsundere high school girl with a witch hat who has her own circumstances. Together, they decided to start a new life. Defeating monsters, completing requests, and realizing a slow life! For that purpose—first, escape the dungeon!! "Your job is to protect me from monsters, easy, right?" "What are you expecting from a guy who was almost 40!?" The odd couple of a former middle-aged man and a high school girl, who get along well despite their bickering, aim to become the strongest for the sake of a slow life.

For incompetence, Lewin, a Demon-Tamer adventurer, was banished from the hero's party. Without being acknowledged for his achievements as a commanding officer... However, the moment he comes into contact with Sasha, the Demon King of Death, one of the sealed Seven Demon Kings, he awakens to become a Demon King with the ability to subjugate Demon Kings! Moreover, by shattering the seal, he tames the Demon King, Sasha—— Lewin, backed by Sasha, succeeds in drawing out the Demon King's power and works to subdue all Demon Kings, the root of the strife between the humans and the demons.

A prequel to the main story of Brave Frontier, a popular mobile RPG game. The story centers on Signas, one of the surviving members of the Twelve Guardians, who approaches the hero Vargas and warns him not to make the same mistakes that led his group to their downfall under the conspiracy of a certain God.