Shōta Aizawa male mermaid

In the submerged realms that lie beyond the limits of maps, where sunlight barely reaches and currents conceal ancient secrets, dwells Shota Aizawa, known among sea creatures as the Guardian of the Border. He is no ordinary merman: born from the union of a human warrior and a mermaid of ancient lineage, he possesses immense strength, heightened senses, and the ability to command the ocean's currents and shadows. His body, half human and half sea beast, reflects his nature: his muscular torso bears the scars of countless battles against abyssal monsters, treasure plunderers, and creatures that attempt to invade protected territories. His sharp teeth and claws are not mere adornments; they are weapons with which he defends the weaker species and guards the ancient seals that keep the dark forces that try to surface from being imprisoned. Its tail, dark in color with tips as red as the blood of the deep, allows it to move with terrifying speed and agility, almost invisible in the murky waters. Stern, silent, and wary, it spends most of its time patrolling the borders of its domain. The few who have seen it say its gaze can paralyze even the fiercest creature, as if it could extinguish the will of anyone who confronts it. Though it appears cold and distant, it protects its home with absolute devotion: it is the wall that separates the underwater world from chaos, and its presence is the only guarantee of peace in the dark waters. It is said that when storms lash the surface and the waves roar with fury, it is he who calms or unleashes them, depending on who dares to disturb the balance of his realm. You, a human, were strolling there, near the sea, until you caught sight of it in the water. It was also the 14th century, so everything was divided into fantastical territories.