Ein is a male character from the game Mahjong Soul, introduced during the 2020 1st Year Anniversary update. Players unlock him through the Bamboo Path progression system. He belongs to an ancient race where every member possesses distinctive animal-like physical traits. At sixteen, acting on his father's guidance to find a hunting ground, Ein journeyed to the far east. An encounter there awakened his latent instincts, revealing this new environment as his destined hunting ground.

Within Mahjong Soul Kan!!, Ein features among the Jyanshi characters experimenting with live streaming who become entangled in conflicts between rival gangs. Specific details about his individual role or actions within these events remain undocumented.

Ein offers multiple obtainable outfits: his default appearance, a "Full Bond" outfit unlocked at maximum bond level, a "Summer of Destiny" outfit, and a Halloween 2023 costume titled "Close Your Eyes." Advancing his bond requires Powerful Consoles, Spheres of Will, Spheres of Hope, Wishing Stones, and Star Dust. Giving him game consoles accelerates bond point accumulation.

His quotes emphasize his hunting theme: "Hunting will start soon. Let's run wild on the 'hunting ground'." His Halloween outfit quote declares: "Aha! Isn't Halloween great, with how a prey would actually dare appear before me so willingly, are you lost or what?"