The Fourth Squad (第四分隊 Daishi Buntai?) is a major division of the Survey Corps. It was formerly led by Squad Leader Hange Zoë, including its subset Squad Hange (ハンジ班 Hanji-han?) a team consisting of a number of the Fourth Squad's high-ranking officers.
As veteran soldiers of the Survey Corps since before the fall of Wall Maria, several members of the Fourth Squad partake in Commander Erwin Smith's plan to capture the Female Titan in the Titan Forest during the 57th Expedition Outside the Walls. When the Female is captured, Captain Levi Ackerman and Squad Leader Mike Zacharias are unsuccessful in their attempts to sever its limbs. Keiji reports their failure to Commander Erwin, who orders for explosives to be brought out to dismember the Female Titan's hands. Before they can make further attempts, the Female Titan calls all nearby Titans towards her. Abel prepares to combat the Titans as they approach, only to find that the Titans are ignoring them in favor of reaching the Female. At Erwin's command, the veterans attack the Titans devouring the Female Titan until Erwin orders for their forces to retreat to Karanes District.
Some days later, Hange's squad participate in the Stohess District raid to capture Annie Leonhart. When the initial capture plan fails and the Female Titan transforms in the city, Abel, Keiji, and Lauda pursue the Female as she escapes to Wall Sheena, though their pursuit is cut short when the Female Titan runs into an open area where they cannot maneuver in their equipment. As the Female Titan overpowers Eren's Attack Titan, they advance in an attempt to cut off the Female's escape, though she outpaces them and begins to climb Wall Sheena.
Once the Female Titan is defeated and Annie encases herself in a crystal-like hardened substance, Keiji angrily attempts to break her out of her crystal, only to be stopped by Squad Leader Hange. While the Survey Corps covers Annie's crystal and takes it away from the scene, a Colossus Titan is seen inside of Wall Sheena where the Female Titan's climb damaged the Wall. Hange is approached by Minister Nick, who urges them to cover the Wall Titan before sunlight can shine on it. Hange is joined by Rashad and others in their squad to cover the exposed part of the Wall. Hange later interrogates Nick on the spot, demanding to know what he and his church know about the Walls, but Hange's questions are met with no information.
Soon after the defeat of the Female Titan, the Fourth Squad joins the Stohess District Survey Corps operatives on the journey to Ehrmich District to assist in the sudden Wall Rose invasion. While in Ehrmich, Hange receives information concerning Annie's connection to Reiner Braun and Bertolt Hoover. After some discussion, the soldiers present begin to suspect the two to be possible accomplices to Annie. To avoid unwanted conflict, Hange orders all soldiers present to keep the information confidential until Reiner and Bertolt can be confronted in an underground location.
The Survey Corps continues further into Wall Rose to aid in the efforts to locate the breach in Wall Rose, choosing Utgard Castle as a point of reconnaissance. Upon their arrival, they find Survey Corps recruits of the 104th Training Corps battling the Titans amidst the collapsed castle. Hange's squad quickly eliminates the remaining Titans and retrieve the eviscerated recruit Ymir, who possesses the power of the Titans.
The soldiers regroup atop Wall Rose near to the ruins of Utgard where Nifa and Rashad check on Ymir's condition, noting that she is unconscious but healing gradually. The soldiers are met by Captain Hannes of the Garrison's advance unit. Hannes reports to their surprise that no hole was located in Wall Rose. With no set plan of action, Hange announces that they will relocate to Trost District and await further orders. However, at this time Reiner exposes himself and Bertolt as the Armored and Colossus Titans, respectively, moving the soldiers into action as the two transform atop Wall Rose in a sudden attempt to capture Eren.
While Eren battles the Armored Titan, Hange's Squad attack the Colossus Titan. Noting its slow speed, they are confident that they can kill Bertolt quickly, but their efforts come to a halt when the Colossus Titan emits a barrage of hot steam. Due to the strong winds, Hange's squad is unable to approach the Colossus Titan with their maneuvering equipment. Taking Team 1 of her squad to assist Eren, Hange orders for Lauda to lead Team 2 on standby near the Colossus Titan while Rashad leads Teams 3 and 4 to flank the Colossus Titan on the opposite side.
Team 1 observes Eren's battle with the Armored Titan from a distance, urging him to exploit the Armored Titan's weak points to gain the advantage. Eren's tactics and the techniques learned from Annie during their training days succeed in bringing down the Armored Titan. However, Reiner calls out to Bertolt for assistance, and the Colossus Titan breaks free from Wall Rose and comes crashing to the ground below. A soldier atop the Wall urges everyone to move out of the way, but the ranking officers in Hange's teams are caught in the Colossus Titan's explosive impact, leaving them all heavily injured or unconscious.
When Commander Erwin joins the soldiers atop Wall Rose with reinforcements from Trost, Hange and their officers are still too injured to join in the mission to rescue Eren, and it is unknown if any subordinate members of the Fourth Squad were able to participate. Despite their injuries, Hange points out a nearby Titan Forest near to where Reiner and Bertolt fled after the battle. Assuming the two would have to rest for the night before continuing to flee to their "hometown," Hange urges for the able-bodied soldiers to pursue before nightfall.
Members of the Fourth Squad join Hange and Levi Ackerman's Special Operations Squad in a remote cabin to discuss their next move in the aftermath of Minister Nick's death. While there they assist the testing of Eren's Titan abilities.
After Dimo Reeves baits Djel Sannes of the Interior Military Police into a trap, the Fourth Squad joins Squad Levi a different cabin that they are using as their new hiding place. Moblit Berner assists Hange and Levi in interrogating Sannes. The MP eventually breaks and confesses that the Reiss family is the true royal family. Nifa is dispatched to bring this news to Erwin.
Hange leaves most of their squad in Levi's care as they run off with an urgent question for Erwin. Nifa returns shortly after Hange's departure, to find both squads assembled with the addition of Dimo and Flegel Reeves. Levi tells her she can speak in front of them, so she brings up Erwin's plan to replace the current king with Historia Reiss. Once Historia agrees, Nifa presents the details of the operation. They will hand over Eren Yeager and Historia to Dimo Reeves, who will turn them over to the Interior Military Police. The two squads will then follow the MPs to their destination, which they expect will be Rod Reiss, the true ruler of the Walls.
The hand off does not go as expected, resulting in Eren and Historia being captured. Dimo Reeves is killed and the Survey Corps is framed for the murder. Nifa, Keiji, and Abel accompany Squad Levi to Stohess District as they track the Interior Military Police. They stake out an inn where the MPs are staying in disguise with their captives hidden in coffins. However, they are ambushed by the Anti-Personnel Control Squad and Nifa, Keiji, and Abel are all slain before they can react.
That evening, Hange and Moblit Berner pay a visit to the Berg Newspapers where they discover that reporters Roy and Peaure do not have much choice in what news they deliver. Hange asks them to report the truth for one day. With the reporters in tow, Hange and Moblit go to rescue Flegel Reeves from the MPs who are trying to silence him. Flegel manages to get one of the MPs to publicly spill the truth about the death of Dimo Reeves and Hange tells the reporters that the truth will not spread on its own. Peaure convinces Roy to run the story.
After the charges against the Survey Corps are cleared, Hange catches up with the Special Operations Squad and Levi apologizes for having lost the soldiers they entrusted to him. Hange is saddened by the loss, but has a lead to those who killed them.
The Fourth Squad is ordered by Erwin Smith to go with Squad Levi and engage the Armored Titan, using their Thunder Spears at their squad leaders' discretion. The squad is successful in heavily damaging the Armored Titan but makes a hasty retreat after the sudden appearance of Bertolt Hoover and expectation that he will transform into the Colossus Titan in an explosion of steam.
To Hange's relief, Bertolt aborts his attack out of concern for Reiner Braun. Hange orders both squads to continue as planned to finish off Reiner and eliminate Bertolt. However, Armin requests a chance to negotiate. While he does, members of the Fourth Squad head back to Reiner. However, when they arrive they discover the damaged Armored Titan is now lying on its back so they can no longer reach the previously exposed nape.
Hange notices Bertolt has left Armin and has started to ascend into the air. Wary, Hange calls for the squad to pull back, but they do not have enough time. The squad is completely obliterated by the impact of the Colossus Titan's transformation, with the sole exception of Hange, who is spared by being pushed into a nearby well by Moblit Berner.