Mission Mermaiden ~Hasumi and the Deep Sea Sisters~ is an adult-oriented action platformer set in the year 2101 AD. The game follows a heroine named Hasumi who is sent to the Karimantan Jungle to investigate rumors of a biological weapon following an alien invasion. Game Premise and Narrative
Mission Mermaiden Hasumi and the Deep Sea Sisters Verified
The Mermaiden withdrew and then, to Hasumi’s surprise, moved its crown into a slow, spiraling dance. A faint column of heated water trailed in its wake; instruments recorded microcurrents and mineral concentrations consistent with hydrothermal seep activity. Hasumi realized what the creature guarded: a field of mineral vents and an unusual chemical bloom where rare metals precipitated—resources the world above might envy, and ecological wonders that deserved protection. mission mermaiden hasumi and the deep sea sist verified
The submersible found the phenomenon at 4821 meters. At first there was only empty blackness, then a brushstroke of silver as micro-organisms reacted to the sub's lights. Then the water shifted, a slow, vertical bloom: a column of soft violet light edged with pulsing gold, like an opening flower, and at its center a silhouette—elongated, undulating, crowned with filaments that scattered bioluminescence like a halo.
It didn’t explode. It simply… ceased to have ever been. The geothermal vent roared back to life, free of corruption. The neural cords in the walls dissolved into harmless silt. The pressure normalized. And the Sist’s frequency vanished, leaving behind only the natural, beautiful chaos of the deep. Mission Mermaiden ~Hasumi and the Deep Sea Sisters~
Weeks later, when policy makers argued in locked rooms about permits and resource extraction, Hasumi found herself watching the ocean at dawn from the ship’s rail. Sist, awake in the ether, shared a line of analysis.
The Setting: Much of the action takes place in a submarine-like structure within the ocean. Gameplay Mechanics A faint column of heated water trailed in
When the sampling arm touched the plume, the creature’s crown flared—an expression of attention, not alarm. It did something unexpected: it wrapped one delicate filament around the submersible’s manipulator like a hand, then retracted with a nod of light. The touch felt almost like benediction.