13 parts Complete Levi Ackerman and his son, Eren, were alone together for over 4 years. Petra Ral-Ackerman died in a car accident when Eren was a year old. At that point, Levi vowed to not love another for a certain reason. During a little trip to the museum, Eren made a friend with a scientist: Hanji Zoe. Not wanting to disappoint his son, Levi allowed the two to get along. Unfortunately, it means that Levi would have to break his vow.