The manga "I Kept Pressing the 100-Million-Year Button and Came Out on Top" centers on Allen, a young man who discovers a mysterious button that grants him the ability to train for 100 million years in an isolated, timeless space. Each press of the button transports him to this dimension, where he undergoes rigorous training without aging. Upon returning to the real world, only a second has passed, but Allen retains the skills and experience gained during his extended training.

Allen initially uses the button to improve his physical and combat abilities, driven by a desire to overcome his weak and bullied past. As the story progresses, he faces increasingly formidable opponents, including powerful martial artists, supernatural entities, and other individuals who possess unique abilities. The narrative explores the consequences of Allen’s repeated use of the button, including the psychological toll of enduring such prolonged isolation and the moral dilemmas of wielding near-omnipotent power.

The series delves into themes of perseverance, self-improvement, and the cost of power. Allen’s growth is contrasted with the challenges he faces in maintaining his humanity and connections to others, as his experiences in the timeless dimension create a growing disconnect from the real world. Supporting characters, such as his childhood friend and rival, add depth to the story by providing emotional stakes and highlighting Allen’s evolving relationships.

The plot balances action-packed battles with introspective moments, examining the impact of Allen’s choices on his psyche and the world around him. The manga’s pacing alternates between intense training sequences and real-world conflicts, creating a dynamic narrative that keeps the stakes high. Through its exploration of Allen’s journey, the series offers a compelling blend of fantasy, action, and character-driven drama.