Mari's not just meeting historical figures, she's actually changing how they think about their own discoveries. Each episode pulls off the trick of making real science feel like adventure, not a lecture. The mystery of her missing father threads through every jump backward, turning what could be a dry educational show into something that actually makes you care whether she makes it home.

Three years after her scientist father Eiji disappears, Mari Hayase still has the pendant he left behind, a device called the armillary compass. When she comes across a mysterious book, the compass lights up and throws her into the past. With her best friend Waka Mizuki and Waka's brother at her side, Mari jumps from era to era hoping to find her father. Along the way she meets eight famous scientists and inventors whose work transformed how people understood magnetism and electricity, including Benjamin Franklin, Alexander Graham Bell and Thomas Edison. The 12-episode sci-fi adventure is adapted from a 1983 book by Japanese educator Kiyonobu Itakura about the history of discoveries in magnetism and electricity.