Takuya doesn't know his father is alive until the device proves it. The show doesn't waste time convincing you that parallel worlds matter, because the first rule of time travel fiction is simple: if your dad vanished into another dimension, you're going after him, logic be damned. Every choice branches into a new world, and every world has a version of the people he loves wearing a different face. The pacing stumbles in the middle stretch, stretching mystery past the point where it grips. But the core emotional engine never quits: a kid with a device that lets him rewrite reality, trying to find one version of his father where things didn't break. That desperation is what keeps you watching.

Takuya Arima is a student whose father, a historian known for his research, has recently gone missing. Over summer vacation, Takuya gets an odd package from him, along with a letter claiming that many parallel worlds exist. Takuya brushes it off at first, then finds he has a device that can carry him into alternate dimensions. Now he wonders whether his father might still be alive, and where he could be. The story mixes science fiction, adventure, action and drama.