After the huge disaster and rescuing Eren, they have found themselves into another person's life. More mysteries are to be solved and it turns out that they found a mysterious girl living in the woods. Her name was Kousagi Shimizu the daughter of Dr. Shimizu as she meets the Scouting Legion and becomes friends with Chibi Chibi. However, a dark side of herself has approaching her arrival as she tries to tame herself from it. Other news was that she is Eren's guardian that she is capable of protecting him along with Chibi Chibi that she will soon be awaken and reborn. Historia's father tells her that in order to bring her sister back was to eat Eren. Kousagi on the other hand will change it from making her doing when the force of evil takes over to put an end to it all.