Shinigami(死神) are basically immortal gods that are the personification of Death. They are also referred to as “Grim Reapers” or simply "Death gods". They help maintain the balance between life and death by ensuring that the consumption of human souls is restricted. If enough souls are consumed, then a Kishin(鬼神) may rise up, upsetting the balance by killing and consuming the souls of those murdered. They are an ancient race, predating the Witches, and there are only five located on Earth during the course of “My Destiny My Fervent Plea”. After the events of the story and its sequel, two more appear on the scene for obvious reasons.
Lord Death is the first and foremost, not to mention the most powerful. His son, Death the Kid, is only a fragment of him, along with his younger sister Hannah .
The first, the most powerful and most ancient Shinigami currently alive. Lord Death originally protected the Earth with Eight powerful gaurdians, each preumably armed with a Death Scythe or other form of weapon. However, Lord Death's most powrrful warrior, Asura, turned against him, becoming perhaps the first Kishin. Lord Death defeated and sealed Asura in a bag made of his own skin. This bag was locked deep within the bowels of Death City and Lord Death routed his own soul into the city's foundations to keep Asura from ever escaping. Now trapped in his own Soul, Lord Death started an academy for meisters and weapons, to both train Meisters to fight witches and Pre-Kishin and to also gather the desendants of the Magic Weapons created by the Witch Arachne.
Lord Death's eldest child and presumable heir. Death the Kid has an OCD surrounding symmetry compelling him to make everything in his imediate surroundings symmetrical. Because of this he fights with two Weapons, Liz and Patti Thompson, the demon pistols. Identical in weapons form, Kid is frustrated to no end that their human forms are so different from each other. Kid is also frustrated with the three white lines in his hair that only appear on the left side. The Lines of Sanzu are conduits for Kid's true Grim Reaper powers and whenever one connects, Kid's powers are boosted dramatically. It is suggested in the manga that once all three connect, Kid will become a fully fledged Grim Reaper.