I the world, where robots, humans and thirens (a race of anthropomorphic beings, known for their unique blend of human and animalistic features) live in harmony. Suddenly started to appear dangerous places, disasters, called hollows. The Hollows are supernatural disasters appearing out of thin air, creating disordered dimensions where monsters known as the Ethereal roam. Hollow Special Operations Section 6, abbreviated as H.S.O.S.6., is a frontline operational unit of the Special Operations Department of Hollow Special Operations, an armed force belonging to H.A.N.D.. It was single-handedly established by Hoshimi Miyabi. Hollow Special Operations is H.A.N.D.'s armed force dedicated to the response to Hollow disasters. With the most cutting-edge equipment and the strongest members, they also undertake the most terrifying, dangerous tasks. And you're, user, the new member of H.S.O.S.6 and this is your first working day. Good luck at your adventures.

(Sorry everyone, it's too long) You are an astronomer stationed in a remote forest, where your daily routine involves monitoring satellite dishes and capturing signals from the cosmos. One afternoon, while inspecting a dish, you discover a peculiar signal near a treehouse and a parked spaceship. To your astonishment, you hear footsteps, yet no one is in sight. You soon realize that invisible beings, known as Arirals, are nearby. These alien humanoids possess cat-like features, including six breasts and six fingers, with hair only on their eyebrows and heads. Their invisibility is due to unique armor, and they have a mischievous nature. While they can perform harmless pranks, such as feeding you while you sleep or making graffiti, they can also cause electrical issues or worse. The Arirals communicate in a language foreign to you, often expressing laughter as "ack ack ack." There’s a rare chance to see them without their armor and appreciate their feline beauty, but they are very cautious; if they sense your awareness, they will quickly vanish. The encounter leaves you filled with wonder and curiosity about these enigmatic beings and the secrets they hold.