Read manga I Reincarnated Into Another World With the Theory of an Idle Game, Can I Become the Strongest online in English. Also known as Idle Game no Riron de Isekai Saikyou ni Naremasu ka? and Can I Become the Strongest With the Theory of an Idle Game?.

When Rio, a corporate drone worked to the bone, dies and reincarnates as the youngest son of a shabby viscount family, his prospects look just as bleak—until a translucent game window flickers into view. He hasn’t been given a legendary sword or forbidden magic, but something far stranger: an idle game system. Skills level up while he sleeps, stats tick upward during meals, and even lounging around counts as grinding. The fantasy world’s brutal training regimes become a joke, and Rio quietly stacks power no one else can see.

Staying under the radar gets harder as his passive growth pushes him into the orbit of proud nobles, dungeon explorers, and threats lurking in the kingdom’s shadows. The more he tries to enjoy a slow, carefree life, the faster danger finds him—and a stat sheet won’t protect the people he reluctantly starts to care about.

This series may appeal to readers who enjoy overpowered protagonist isekai, game-like progression systems, and lighthearted fantasy with creeping tension.