Well I read something a little while ago and I forgot the manga title.
What happened in the manga was this guy supposedly killed his family and his sister comes back as a shinigami/death god/ angel of death or what ever you want to call it and tells him she came to take his soul and grant his last request. The last chapter I read had the brother helping out the shinigami with tech problems and the both siblings were going to be sent to hell i think. They come up with some scheme so they get reborn or something and thats how the chapter ends.
Any help would be appreciated :]

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Some guy lurking, but not doing it very well

Shinigami-sama ni Saigo no Onegai o should be it.

yup thats it, thanks I forgot to add it to my reading list lol >.>

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Some guy lurking, but not doing it very well