After returning from school, 12 year old Midori receives a message on the social network from a stranger. He invites her to play the "Blue Whale", a mysterious and dangerous game, at the end of which Midori should become a whale...

After returning from school, 12 year old Midori receives a message on the social network from a stranger. He invites her to play the "Blue Whale", a mysterious and dangerous game, at the end of which Midori should become a whale...