The Aquarium does not dance: The Idol Who Wants to Die

This is the story of the twenty-four hours leading up to a death.

"I-I just don't want to suffer when I die. Is it true I can do that here?"

Hikaru, a failed idol, goes to Bianca Aquarium to have her wish to die granted.

"It is. I'll make sure that you die without pain. But if you die on your own... I will murder you."

There, she meets the mysterious Holo. A cleaner wrasse who is the self-proclaimed cutest maid in the world, Holo is imperious and pushy.

Holo has been searching for people who will allow him to perform the Dirge of the Abysmal ritual upon them because they're willing to die. However, just as he is about to perform it on Hikaru, he discovers that something has gone terribly wrong. The ring with the blue stone, which is essential to the ritual, is a fake. The real one was stolen.

Chasing down the thief brings Holo face-to-face to a strange figure with pale skin and red eyes, who says, "You've been allowed to run free too long, cleaner. Or should I say... murderer?"

Then they disappear, as if into thin air.

"Without that ring, neither your wish nor mine can be granted. We need that ring, Hikaru."

Will Hikaru's wish come true?

What is the wish that Holo is trying to make true by sacrificing so many people?

[Taken from Steam]