"Water gods of the ancient Azumi tribe, versed in the way of water."
The Azumi are a tribe from Japan who excelled in fishing, it is said they are the descendents of Amaterasu, Tsukuyomi, and Susano-o, the three gods sired by Izanagi after he returned from Yomi, land of the dead. The deity Azumi is said to be a guardian of the people after which it's named, and can control the element of water similarly to its sibling deity, Isora.
"Origin: Japan. Water gods of the ancient Azumi race. They excel at using water magic. It's said they come from the south. Though they may prefer living in the sea, they have scattered across Japan in peace."
—Shin Megami Tensei A-Mode DDS Dictionary
Shin Megami Tensei IMAGINE
"Water gods of the ancient Azumi tribe, versed in the way of water. Often referred to as Azumi-no-Isora. They are said to have arrived in Japan from the south, preferring a life at sea to a life on land. The god Azumi-no-Isora-Kami is their chief. Later, having settled peacefully in Japan, they scattered throughout the land. Azumi-no-Isora are also called Azumi-no-Isora-Maru, and it is for this reason that boats in Japan are named with the suffix "-maru," as a prayer to the Azumi for protection against disaster at sea. Azumi are identified with the shrine god Amenokoyane."
—Shin Megami Tensei IMAGINE Compendium
Azumi can be contracted on Nakano field. They appear as enemies in the early kappa events, on Ikebukuro field, and within Nakano Stone Site.
Shin Megami Tensei: Strange Journey
"A water deity of the Azumi, a Japanese fishing tribe. It can control water. The three gods born from Izanagi after he returned from Yomi are said to be the Azumi tribe's ancestors."
—Shin Megami Tensei: Strange Journey Compendium
Azumi can be found as a common recruitable enemy in Sector Bootes.