Heir to a long line of Shinto priests and exorcists, Nami is the most tranquil member of the AMP. She is also the tidiest, often shown cleaning up after Katsumi and Kiddy. She uses holy water and ofuda (paper charms with kanji written on them) with varying degrees of effect on Lucifer Hawk. She wields the Kirin Dagger and White Tiger Sword, two of the five sacred relics of the Yamigumo family. Nami also has the ability to detect Lucifer Hawks nearby.

The Yamigumo family owns a Shinto shrine three hundred meters underground. Nami typically wears a kimono instead of the AMP uniform.

Her elder sister Nana has a connection with Mana Isozaki, but its nature is unknown. Her late father Razan Yamigumo initially fought against Gigelf Liqueur, but later joined him in his battle against the Lucifer Hawk.