Ahem embodies the Spirit of the Earth within the story's mythology. Rumors suggest he was once married to Mii, the spirit of flowers and fertility. His mythological basis loosely draws from Morufonu, a Vanuatuan earth god, and occasionally Aluluei, a Micronesian god of navigation. His name "Ahem" evokes connotations of pride, importance, and necessity in Indo-Aryan languages.

He first manifests to Natsumi Rokudo in a dream after she accidentally breaks the seal imprisoning Ongo, the spirit of wood and destruction. During this encounter, he presents her with Mii's necklace and performs a specific, suggestive dance. He describes the dance as protective against danger, though its true function is to unleash Mii's spiritual essence and transfer her powers to Natsumi.

His primary abilities target evil forces. He wields a spear capable of destroying malevolent entities, which he can enlarge into a pole for greater reach or impact. During a critical confrontation where Ongo reverts to his destructive form, Ahem intervenes directly to eliminate the evil spirit within Ongo, restoring balance.

Beyond the original OVA, drama CD narratives expand his role. In one, he visits Natsumi and recounts a tale of them collaborating to defeat a dangerous monster in an apocalyptic future. In another, he provides mental coaching and strategic support during a battle against a separate monster threat, working alongside Mii, Ongo, and Rongo.

A minor incident highlights his occasional fallibility: boarding an incorrect flight leads to unintended arrival in Australia in some versions or Los Angeles in others. This offers a lighter aspect to his typically serious guardian role.

His actions consistently focus on guiding Natsumi, facilitating Mii's influence in the human world, and confronting supernatural threats to maintain harmony between the spiritual and earthly realms.