As an Attacker with over 7000 points, Kumagai is individually more powerful than C-rank trainees and some B-rank agents. In reality, her combat ability exceeds her score, which is relatively low due to her often serving as Rei Nasu's bodyguard. She gave proof of the solidity of her guard against Yūma Kuga and Kō Murakami, who, despite being far more skilled than her, were unable to dispatch her for the duration of the three-way fight, and she proved difficult for Murakami to defeat even in a one-on-one confrontation, although she was ultimately unable to injure him in any way. Together with Nasu she was able to force Wen Sō, who was noted to be A-rank level or above, to bail out.
Aside from her swordsmanship, in battle Kumagai can rely on a noteworthy awareness of her surroundings and perceptiveness. During the three-way fight she predicted that Murakami would be the one to make a move to break the stasis and synchronized her attack with his when he launched it to further pressure Yūma. Despite being outskilled by her opponents, she had enough attention to spare to direct Akane Hiura and signal her when to shoot. She gave further proof of her power of observation and multitasking ability against Wen Sō, when, despite the severity of her injuries and the number of opponents she was facing, she was able to discover the mirrors conjured by Servitora. Shortly afterwards she understood how the Neighbor's image was replicated and deduced that she could find the original through a small detail of her uniform, although she failed to see through the additional two traps Wen Sō laid until after she was defeated.
Though Kumagai's fighting style consists in holding her Kogetsu with both hands and summoning Shield to defend as needed, in the match against Tamakoma Second and Suzunari First she efficiently incorporated Meteor, which she had never used before, through a mixture of improvisation and mimicry of Nasu's movements that earned her the commentators' praise.
|Yūko Kumagai's Triggers|
|Yūko wields her Kogetsu with both hands, as, although she is capable of putting up a fight by holding it with only one hand, her bladework becomes slower. She is more proficient with a Kogetsu than her solo points suggest, and despite being far less skilled than Border's top Attackers, her guard is solid enough that two of them were unable to break it in a three-way confrontation. She is particularly famed for her counterattacks. Since she frequently blocks enemy swords with her own, she had it modified to include a cross-shaped tsuba. In the match against Tamakoma Second and Suzunari First she spawned without her sword and conjured it only when she thought she would need it, although it is unknown whether this is her preference or if she did so because the circumstances required her to move quickly. Kumagai is first seen using Kogetsu in Chapter 96 (Episode 44 in the anime).|
|Kumagai's usual fighting style consists in holding her Kogetsu with both hands and activating Shield when needed, and specifically a hexagonal focused one against other Attackers. She appears to prefer to block with her sword alone, saving her Shield only for emergencies. Murakami in fact displayed the ability to break it with a single swing, and although the focused Shield allowed Kumagai to avoid bailing out, it was unable to prevent her from taking considerable damage. Against ranged fighters she deploys a hexagonal Shield from the back of her right forearm which protects most of her upper body. Kumagai is first seen using Shield in Chapter 99 (Episode 45 in the anime).|
|Kumagai equipped Meteor in the match against Tamakoma Second and Suzunari First to demolish the bridge. Despite being her very first time using it, or any Gunner Trigger as a Shooter, she managed to make up for the loss of an arm with it and hold her own against Murakami, which earned her the commentators' repeated praise. According to herself, imagining Nasu's fighting style helps her move more precisely. She has displayed the ability to quickly divide and scatter her bullets around herself, shooting both directly at her opponent and at the ground around him to keep him at a safe distance, as well as to place a static bullet on the hilt of Murakami's weapon right before bailing out. It is nonetheless worth noting that some of her shots missed even from up close, and that the cause of her defeat was Murakami turning the explosive properties of the bullets against her. The first and only time she was shown dividing her trion cube, she split it in 27 pieces. It remains unclear whether Kumagai permanently added Meteor to her Trigger Set after the match. She is first seen using it in Chapter 99 (Episode 45 in the anime).|
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