M-Preg manga or male pregnancy manga is a sub-genre of Yaoi romance where men can get pregnant by other men or even by women. There are two different types of mpreg manga; shifter and non-shifter and the later is often refereed as omegaverse. In the shifter mpreg romance manga, (where the characters involved are shape shifters such as wolves and other animals who can become something else) there is a hierarchy of wolves and animals which can be divided into alpha, beta and omegas.
The alphas are always in charge and are considered the top dogs as their names implies they are alpha men, meaning they are usually the dominant figure in every relationship. Betas are the second in command and are bound to obey the alpha’s. This usually means that beta men play the role of the uncle characters.
The omegas are the nurturing types and more feminine in mature, they are usually the ones subjected to senual favors and are the ones that are likely to get pregnant. Some manga like Tokyo Renaikitan and Yokubou Shounen are based 100% on this concept
The non shape shifter mpreg manga world is pretty much similar, but in this world the betas do not exist. However, the alphas and the omegas have the same characteristics. How these omegas get pregnant depends on the manga. Usually the manga does not give a clear biological reason but operates on the principle that if vampires and werewolves can exist then why can’t male pregnancy.
Aspects that separate mpreg manga from other Yaoi Manga:
One of the main aspects of the troupe is the concept of heat. It is a period when an omega wants se9x and cannot contain himself, this is also accompained by another phenomena called knotting which induces pregnancy in the omega.
On Mangazuki we have a large collection of these manga. This usually includes a good amount of kin)k. There are some manga in which the alpha can sense the heat and his body knots in response to it. Manga such as these usually contain a large amount of nudity and are loved by the Yaoi Manga community.