Naomi is a new character introduced in Metal Slug Attack.
Naomi is one of the Rebel Army's instructors and is also the an officer of the Aviation Corps. Like Donald Morden and Allen O'Neil, Naomi originally served in the Regular Army, though she left when Morden decided to form the Rebel Army to combat the corruption of the Regular Army. As a former instructor in the Regular Army, she is also acquainted with Sophia.
Now serving as a Rebel Army instructor, Naomi considers Chloe as her favorite student because she never makes a mistake. However, she is feared by her own corps due to her merciless, but effective training. Along with being a proficient instructor, Naomi is also part of the Aviation Corps, commanding Flying Taras to attack her enemies. She is also capable of using Denturions (which have structural defects) efficiently.
First appearing in "Material Affection", Naomi is first seen instructing a group of new recruits with Edda, the latter having joined because of Morden's orders. She is annoyed with the tardiness of the recruits and labels them as "fertilizer" (meatshields). Edda asks Naomi why she is training the recruits when the base is under attack by the Invaders; in response, she replies that they will never be good soldiers if they don't train in such scenarios. Unsurprisingly, Naomi completes the training session with all recruits safe and accounted for.
When another Rebel base is under attack by what appears to be a Martian attack, Naomi is impressed by Grazia's motivation to continue fighting, and offers her Aviation Corps to provide air support during the battle. The Dai-Manji involved in the battle flees shortly afterwards, where she comments that it's the first time she's seen an enemy flee rather than surrender.