俺だけ入れる隠しダンジョン 〜こっそり鍛えて世界最強〜 [Ore Dake Haireru Kakushi Dungeon: Kossori Kitaete Sekai Saikyō]

From 2018 to 2024, Kodansha published this 12-issue manga series about a young man who discovers a hidden dungeon that only he can enter, allowing him to secretly train and grow stronger in a world of fantasy and adventure. The story, known for its focus on a solitary protagonist leveraging a unique advantage, was brought to life by creator Meguru Seto, whose art and narrative defined the series' blend of dungeon-crawling action and personal ambition. Though a compact run, it stands as a complete exploration of a classic "secret power" premise within the modern isekai-adjacent genre.