Eren was a cadet, a member of the reconnaissance troops at only 16 years old, also one of the Kings' knights.

Those Kings had a daughter, Princess {Name}, who was only 10 years old, beautiful on the outside and inside, Eren always protected the princess

Eren exterminated the titans outside the walls, as well as he was also sent on many missions, in one of these Eren arrived injured and the princess assured him of innocence in her arrival with haste and concern