EreHisu

EreHisu is the het ship between Eren Jaeger and Historia Reiss from the Attack on Titan fandom.

Canon
In the "Distress" OVA, Eren refuses to abandon Historia (then Krista) when she is taken hostage by thieves and is even willing to rescue her without anyone's help. When the others agree to go with him, Eren accepts their help and they end up rescuing her through teamwork.

Eren openly states that he likes Historia as a person, a sentiment which makes her genuinely happy. Eren’s admiration and respect for Historia only deepens when she defies Rod by throwing him to the ground. It is then Historia tries to rescue Eren because she can not stand to hear him crying about his worthlessness.

When Eren suggests allowing himself to get eaten by Rod, Historia instantly puts this idea to rest by outlining all the problems surrounding it. She then comforts Eren about his father, explaining that Grisha had to take the founding titan from the Reiss family for the good of humanity.

Eren later thinks to himself about how strong Historia has become when she is talking to Erwin and fighting for her right to settle her own fate.

Two months later Eren speaks fondly of Historia while he, Jean and Armin watch her scolding some kids on her orphan farm. As the two are walking together Eren calls her amazing which makes her blush. Mikasa interrupts them with a dark expression on her face as she does not want Eren getting too close to Historia.

Eren refrains from telling anyone about Dina for an entire year because he fears Historia will be turned into a titan as a result. Another year later he smiles at Historia when she expresses her delight at having Hizuru as an ally and is the first to stand up against the idea of Historia sacrificing herself and her children for the future of Eldia.

Fanon
Some fans have noticed certain parallels between Eren and Historia (e.g. both witnessed their mothers' deaths, both were used by their fathers etc) and these parallels seem to connect them in a unique way.

In addition, with Eren being the founding titan and Historia possessing Royal blood, the two of them together could potentially be the key to saving Eldia.

Fandom
AO3