Jimi na Ojisan, Jitsu wa Eiyuu deshita. Jikaku ga Nai Mama Musou shitetara, Mei no Dungeon Haishin de Sarasareteta you desu

Keita Sato, a 41-year-old single office worker, is stuck in a soul-crushing corporate routine, buried under endless stressful tasks. His secret escape? Sneaking into real-life modern “dungeons,” where he treats terrifying monsters like baseballs in a batting cage, smashing them away to blow off steam. One day, his curious niece Hikari secretly tags along and livestreams his monster-busting spree—sending the internet into a frenzy as his insane strength goes viral! Without realizing it, Keita draws the attention of millions of viewers and top-tier streamers, setting the stage for an unexpected journey from overworked salaryman to legendary internet sensation.