Sekai Saikyou Inkya, Dungeon Haishin de Oku Bazuru: Haishin Kiriwasure no Sei de, Ukkari Level Counter Stop shiteiru Koto ga Bareteshimatta

In modern-day Japan, the sudden emergence of mysterious dungeons across the globe has reshaped society. Amid this upheaval lives Omomo Rei, a complete recluse who has severed all ties with the outside world. While he is an unremarkable loner in everyday life, within the depths of these perilous labyrinths, he stands alone as the only person on Earth to have reached the absolute maximum level. Entirely consumed by his solitary dungeon expeditions, Rei seeks nothing more than a quiet existence far removed from the public eye. His carefully maintained anonymity shatters when he rescues Yuria, a renowned livestreamer boasting ten million subscribers, from a deadly encounter inside a dungeon. Because her broadcast was accidentally left running, footage of Rei's overwhelming power spreads like wildfire, turning the reluctant introvert into an overnight sensation. Thrust into a spotlight he desperately wanted to avoid, Rei finds that his viral fame is only the beginning of his troubles. Instead of returning to his peaceful routine, he is dragged into a sprawling conspiracy surrounding the dungeons' true nature—a mystery entangling both the criminal underworld and the highest levels of government.