it's oldschool life for the simpler days /
it's oldschool life with the simpler ways /
catch me chillin´ like a villain with a thousand plays /
but I know it's not gone - nah it ain't no phase
In Bleach, Shinigamis' (Soul Reapers in the English Translation) main jobs are to send spirits to the Soul Society (aka. the afterlife) and to cleanse Hollows.
In Death Note, Shinigamis are the (original) owners of notebooks called the Death Note. If a name is written in the Note, then the person of that name would die, and the responsible Shinigami would gain life.
Whoever writes a name of a person in the Death Note, that person would die of a heart attack 40 second later, if not specified.
Shinigami are also the primary focus of the popular manga and now anime, Bleach.
Only a Shinigami can put this lost soul to peace.