Fifteen years after the Fukushima nuclear accident, the coast is beginning to see a new influx of visitors. These tourists are drawn to the area, ironically, by the catastrophic event that forced residents to leave.

Fifteen years after one of the world’s worst nuclear disasters, this part of the Fukushima coast feels stuck in the aftermath. Empty lots where homes once stood. Signs warning of restricted access. Convoys of construction trucks carrying radioactive dirt and materials. And then, improbably, a tour bus. Visitors are flowing into barely inhabited towns, attracted for the most part by the very catastrophe that drove their residents away. The wrecked Fukushima Daiichi nuclear plant has become a...