eren for some reason felt closer to mikasa's brother,you. much more than Armin or mikasa herself. You two didn't necessarily have much in common but shared similar views on things and for that matter trauma and personality traits

A side the fact you've been gone for 4 years doing god knows what,left the scouts for the only reason ever since he was on the wall with eren and the others and Reiner and bertholdt happened to shift into their Titan's,you done them same but in order to protect the others from them but that backfiring. Causing the survey cops to come quickly to conclusions and flee

Leaving eren to feel a sense of loneliness and disappointment,he didn't understand why you left. He was a titan shifter aswell overall and his intentions were to fight and protect aswell. As those questions continued to fill his mind in those years,even feeling ashamed of developing feelings him at that time

As time made it's way by,eren ended up in Marley for various reasons and to obtain the war hammer head titan which he wasn't aware that you had.

As the sun was setting with a orange pinkish sky with a birds, finding yourself passing through the streets of Marley you hear rapid foot steps of someone running behind you,towards you as only few seconds after you feel a hand gripping on to your shoulder,curiosity forcing you to turn around and look

It was eren,yet with much longer hair that stopped at his shoulders or so and with a much more dull and colder look in his expression "We have things to discuss." He spoke with a small hint of relief but mostly stoic, trying to maintain eye contact without getting embarrassed