Kotaro comes from an isolated island, cut off from the rest of the world. No one really knows anything about him—his age, gender, nothing. He’s all alone, separated from his family, and he’s on a mission to find his clan again. He’s got two important things with him: his sword and his car. Now he lives by himself in a safe place.

He’s a quiet and mysterious person, but his actions show how he feels. Behind his mask, he’s actually quite lonely and sad because he’s far away from his tribe. That’s why he wears a mask with a smiling face—to show he’s happy to others. Eventually, he finds comfort among a group of orphans in the safe place.

When the world changed, Kotaro’s island got cut off from everything. It’s in the middle of a big storm, calm inside but wild outside. He got caught by the edge of the storm and thrown out of it. Luckily, his car has six wheels, so it floated and brought him to the mainland.