Mike is a tall and well-built man. The bangs of his shaggy light hair are parted down the middle, and he has a dark mustache and beard. He is typically dressed in the standard Survey Corps uniform but also wears the signature cape during expeditions.
Mike is almost always seen with a serious, calm expression, appearing to be a quiet man, rarely speaking unless it concerned a more serious matter. He is a loyal member of the Survey Corps and an adamant vanguard for mankind's freedom.
In the year 844, prior to the fall of Wall Maria, Mike is a member of the Survey Corps under Erwin's command who is a Squad Leader. As one of Erwin's most trusted comrades, Mike takes part to the capture and the recruitment into the Survey Corps of Levi and his friends. During the mission, he teams up with Erwin to get Levi and is the first to attack him but is quickly defeated. Erwin eventually comes to attack their target. When he is disarmed, Mike intervenes, stopping Levi's gesture and telling him to look at his friends, who were captured by Erwin's squad members. After that, Erwin interrogates the trio, and, seeing none of them was willing to cooperate, Mike begins the physical threats by hitting Levi's head against the ground.
After the rain during the second part of the expedition outside the Walls ceased, Mike and Erwin manage to find Flagon's squad, only to learn a group of Titans killed most of the group before being slaughtered by Levi. When the latter attacks Erwin, Mike goes to help him but is ordered by Levi not to intervene. As the two discuss Lovof's document, Mike worries about Erwin bluntly explaining all his plan to Levi. Eventually, the latter calms down and the three men leave to join the rest of their comrades.
- Erwin Smith - Erwin and Mike work closely together; they appear to get along well and trust each other.