Soulmates.

Such an unbelievable thing, right? That’s what Satoru thought — until The Number was announced by government officials.

Everyone would have a number on either their collarbone, wrist, or ankle. Those who had the same number were soulmates.

Satoru had 3 on his wrist. But he didn’t believe in these things, of course. Satoru wanted to go on with his life.

That changed, when you were brought into the story.