A teenager is transported to a parallel world where everyone who shares his family name is being hunted down by the dictatorial government.

Teenager Tsubasa Sato returns to the parallel universe where demons are out to kill every person with the last name of Sato.

Set in the year 3000 in New Tokyo where this time round, human beings with blood type B are being targeted.

One day, it's decided that all people with blood type B have to be killed. There are people in black costumes who chase after and kill everyone with blood type B. Tsukasa is one of those people. Together with her friend Yui she tries to stay alive and staying alive means running because hiding isn't a solution. On the hunt, they meet Masaharu and together they decide to fight against those black costumed creatures.

When good-for-nothing employee Daichi is attending to a backlog of work, a frightening game of tag targeting people with blood type B begins.