Gun's Sister

Kei has one very important question:
How do you file a complaint against God?

Because last she checked, she wasn't supposed to die.

After accidentally overhearing Grim Reaper getting scolded by God for her very inconvenient, totally unplanned death, Kei is offered a second chance at life. Naturally, she does what any reasonable person would do-asks to be reincarnated into one of her favorite stories.
Good news? Her wish is granted.
Bad news? There's a condition.
Worse news? She can't remember it.
New life? Accepted.
Mysterious condition? Ignored.
Future problems? Not her concern.

Unfortunately... it becomes her concern.

Reborn as the sister of Gun Park, Kei starts her second life with full awareness, caution, and a strong determination to not die again.

And then-

She forgets.

By the age of five the memories of her past life fade away completely, leaving behind only strange instincts, unexplained fears, and a lingering feeling that something is... off.

Now living as an ordinary girl (well, as ordinary as Gun Park's sister can be), Kei grows up unaware that her very existence is a mistake that was never meant to be corrected.

But forgotten things don't stay buried forever.

Especially not when fate itself is trying to fix an error.

And somewhere, beyond her reach, a condition she can't remember is quietly waiting to be fulfilled.

(Just a story with a mix up of many crossovers..even I don't know who ends up coming in every next chapter..🙃)