Midori Schumann is a new character introduced in Metal Slug Attack.
A young girl in charge of the army's weapons and munitions. She was a war orphan, but Marco recognized her talents when he observed her playing and recruited her. She tends to refer to herself in the third-person.
Midori is responsible for creating a vast array of the Regular Army's weapons which are used by several members of the army. She developed the Thunder Shot (occasionally used by Fio), a leg attachment for Rita, the E.G.G., three egg-shaped like drones based on a high-ranking Rebel Army officer's drones which are used by Gisee. She also has several "TETSUJIN-KUN" Slug Armors.
During the Extra Ops titled "Rising Iron", the Regular Army base is under constant attack by the Rebel Army. While he considers re-enforcements, Midori asks Marco if she can join the battle. Eri is initially hesitant, due to the engineer's young age and lack of combat training, but the two veterans do decide to allow her to fight. While Eri advises her to stay within sight, Marco asks her two robots to protect her.
After repelling the attack, the robots bring up a picture of her and her original family, prompting her to cry. Marco asks Eri to console her, since they were both war orphans.
In "United Front the 3rd", Marco attempts to evacuate Midori as the base is being overwhelmed by the Rebel Army and their new weapons. However, Reika and her volunteer corps arrive in time and relive them from the attack.
In the next United Front, Midori presents Marco with a customized Slug Gigant, painted gold to mimic the golden war machines used by the Rebel Army.
Midori later accompanied Marco and Gisee in investigating and destroying a Land Blowfish.
She is briefly mentioned in "The Back You Can't Reach" as the creator of the Thunder Shot.
During Christmas, Midori is excited to see what Santa will bring her and falls asleep for the next day. In her dream, she encounters a Christmas spirit who temporarily turns her into one to search for the other fragments. During this time, she learns more about Christmas. From the Invaders, she learns about family and caring for others. From the Ptolemaics, Midori learns about support and sacrifice. From Nova, she learns about being others' hope. When she wakes up from her dream, she finds Marco and the others asleep in her room, as they attempted to bring her presents but fell asleep when Fio stepped on her sleeping gas toy.
- She is the second Regular Army character introduced by Metal Slug Attack, the first being MS-Alice.
- Midori is one of the few Metal Slug Attack newcomers (alongside Scotia, Anna, and Rita) to have a last name. However, it is not mentioned in-game but only in her official concept art.