For those expecting Attack on Titan protagonists Eren Yeager and Mikasa Ackerman to fall in love with each other at some point of the story, sorry guys, it won't probably happen at all.
Hajime Isayama, the creator of Shingeki no Kyojin (Attack on Titan), might have just dropped the real score between Eren and Mikasa on Volume 3 of Gekkan Shingeki no Kyojin interview.
According to the manga artist, Eren looks at his relationship with Mikasa like that of a mother to his son. He values Mikasa's presence a lot, but at the same time, she reminds him how helpless he is without his foster sister around.
"For Eren, rather than a lover, Mikasa's presence is more like a mother to him. The love towards a mother is considered valuable [precious], however at the same time, there are annoying parts as well [laugh], Isayama stated in the interview (h/t Yusenki)"
Moreover, Isayama confirmed that there will be a point when the young Yeager turns into a man and becomes fully independent from Mikasa.
"Just like towards one's actual mother, Eren will start to grow up when he becomes independent [move away/not dependent on] from Mikasa, I might draw this scene one day."
Unlike other shonen mangas/anime, Attack on Titan doesn't much put emphasis on the leading character's love interest. It shouldn't be surprise given the fact that Eren is still too drunk with hatred toward the titans - the very cause of his pain. Perhaps, until the time when he finally liberates the people from the fear of the Titan, Eren will not learn to love.
As for Mikasa, there is a theory that she's actually Eren's mother, but from the future. I know this speculation is quite mind-boggling since the plot is basically set at medieval period. But hey, the world of Attack on Titan is still pretty much unexplored, and soon more secrets will be unveiled, including the true identity of Eren and Mikasa.