It is revealed that Yui has the heart of the vampires’ mother, Cordelia, transplanted inside her, which is why her blood is of "finest quality".
The drama CDs, which are a major part of the franchise, use specialized microphones to create a 3D audio experience, making it feel as if the vampire characters are whispering directly into the listener’s ears.
The second game (fan disc) introduced the Mukami brothers (Ruki, Kou, Yuma, and Azusa), expanding the plot and adding new dynamics, with four new characters. Diabolik Lovers
The first game, released for the PSP, introduces Yui to the Sakamaki brothers (Ayato, Kanato, Laito, Reiji, Subaru, and Shuu).
"Diabolik Lovers" (ディアボリックラヴァーズ) is a Japanese media franchise initiated by Rejet, known for its unique focus on a "sadistic, normal, masochistic" (SNM) dynamic. It first appeared as a series of drama CDs before expanding into a widely popular, yet polarizing, otome game series, anime, and manga. It is revealed that Yui has the heart
Triplet sons of Cordelia who suffer from deep psychological trauma and a distorted understanding of love.
Yui is frequently criticized for her passivity, but supporters often argue that her endurance in a high-stress, abusive environment shows a different kind of strength. The first game, released for the PSP, introduces
Sons of Beatrix, whose rivalry is rooted in their mother's neglect.