Eren yeager 's relationship with mikasa and armin(contains spoilers)
Mikasa Ackerman : Eren thinks mikasa as his family, true she is the most important woman in his life after his mother. Eren find mikasa annoying at sometimes when she tries to forget her orders and go try to find eren any time. He has yelled at mikasa for treating him like a baby, her younger brother or an old man. Eren himself said that he was jealous of mikasa cause she was really strong and he was nothing compared to her. He still cares for mikasa. In season 2 mikasa confess her love eren thanking him for saving her and wrapping her scarf around her, this happened when mikasa's rib cage was crushed and eren couldn't transform. Dina Fritz titan was coming their way. Eren activates the coordinates because he punched a titan with royal blood. The other titan devouvered Dina Fritz. Later in season 4 Eren calls mikasa when the warhammer titan was about to attack. After launching a thunder spear to the titan's nape mikasa comes near eren and tells him to come home.
Armin Arlet : armin is eren's childhood friend and the person who told him about the outside world. Eren thinks armin as a genius and trusts him to make the right decision like at trost. Armin figured out who the female titan was in season 1, Eren doesn't agree but he had when Annie transformed to the female titan right before him. Armin planned most plans of the survey corps along side Erwin. The scouts figured out many plots because of armin, for all that Eren adores armin. Later in season 4 Eren gives the signal to armin to destroy the ports in Marley.