Necromancy is the study of romances of the human neck.
Important events in necromancy
Necromancy, like everything else in the universe, was discovered by Sir Isaac Newton on January 8th, 1666. He had made a surprise trip to Japan (which he failed to notify his parents of, and thus was grounded shortly thereafter) using the incredible flying machine he had obtained from beating Leonardo Da-Vinci with a branch, who had before him, obtained it by grave robbing Icarus.
Newton first noticed this strange art when he came across some lazy ninji, (a rare thing) and witnessed them fulfilling mass assassinations simply by killing one person, raising their body as an undead servant, and simply watching as the undead creature massacred the rest of the people they were tasked to kill.
When approached, the ninji were so taken aback that Newton could see them (as well as speak flawless Feudal Japanese), that they hesitated in killing him, just long enough for him to send word of the sighting via e-mail to his estranged brother. Newton's brother, intrigued by this, sent a reply, only to have the ninji respond instead of Isaac stating that Newton had been killed and was going to be returned to his home in exactly 14.6 pieces.
Ever since then, Necromancy has unfolded and been whispered about, creating the many, many "definitions" of it seen today.
Human on neck relationships
Human on neck relationships (known as homonecromancy) have become popular ever since some retard watched Dracula and thought he was kissing. It is mistakenly thought by twelve year olds that these relationships result in the creation of hickeys. As implied by the word "mistakenly", this line of thought is a mistake. The real way hickeys are made is
Gay neck relationships
Gay neck relationships (known as homonecromancy) were declared a sin by Gay Neck God. If you're a neck, don't boink a neck of the same sex or else you'll burn in Hell, at least if local red-neck commentators are to be believed.
Necromancy in other cultures
In Mexico, it is customary to ask the other neck if he has been weakened by a swinging neckbreaker. Note that this is only necessary for the necks of luchadores. The other 17% of Mexican necks don't have to do it.
In Japan, necks dress up like tentacles.
Chickens are known to have neck romance with complete strangers, in the hopes of hiding their necks from their sworn archenemy, Farmer Brown.