Tokyo, Planet Earth... High schooler Tatsumi Tatsunami lost his parents at a young age and now works multiple part-time jobs to maintain a hectic but peaceful life with his younger siblings. One day, his body undergoes a sudden change... And now mysterious beings are appearing at his house! To protect the people he holds dear, and to protect Earth (or "area"), Tatsumi must awaken! He had better, because "they" are already here!