After her father left for an assignment in Eastern Europe, Yui Komori was left stranded in Japan. The Sakamaki brothers, consisting of Shuu, Reiji, Ayato, Kanato, Laito, and Subaru, provided her with sanctuary. However, the harmony she had found was abruptly interrupted when the Mukami vampire clan arrived. They aimed to destroy the peace by designating Yui as "Eve" and using her as a breeding tool between herself and a chosen "Adam" to produce strong progeny. The Sakamakis were already fighting over her, and adding more vampires to the mix resulted in territorial battles that heightened Yui's uncertainty. Despite the two clans' attempts to sway her allegiance, Yui remained loyal to the Sakamakis and did not resort to force. In the end, Yui's heart took over, and she found herself unable to let go of her love for one brother in particular.
