While W-0 is away, Leila and the remaining crew at base find themselves surrounded by Britannian Knightmares. Piloting the Vercingetorix, Shin Hyuuga leads the enemy charge, having usurped the position of Grand Master in the Knights of St. Michael. With her core members unavailable, it's up to Leila to protect her comrades, but this may be much tougher than she realizes: a spy lurking among them is finally ready to reveal himself.

Left with no choice but to surrender, Leila arranges a meeting with Shin in order to ensure the safety of her squad. But as negotiations begin to fall apart, Akito and an unexpected ally return in the nick of time to turn things around.

The Ark Fleet has been destroyed, and a significant number of the enemy's troops have been wiped out due to its crash landing. As the remaining forces of the Knights of St. Michael regroup in order to launch a final assault on Castle Weisswolf, the W-0, along with their new ally Ashley Ashra, stand ready to intercept them.

Meanwhile, with his Geass out of control, Shin moves to erase his younger brother's existence once and for all. But Akito, having promised Leila that he will come back alive, refuses to accept such a fate, and the two clash in their final battle.

OVA of Diabolik Lovers included with the upcoming game Diabolik Lovers DARK FATE.

One year ago, a UFO containing 150 aliens crash-landed off the shores of Kasai. Because no one could fix their ship, the Japanese Government decided to bestow upon them the designation "DearS" and make them into Japanese citizens, teaching them the language, customs, and culture of Japan. However, in order for them to become more familiar with human society, a home-stay program has been enacted to allow them to mingle with other humans. One misty morning, a truck carrying a capsule that housed one of these aliens ends up dropping it into the riverbank, releasing her from her confinement. She is eventually found by a high school student named Takeya Ikuhara, who saves her from being hit by a truck and takes pity on her, despite being extremely distrustful of their race and wanting nothing to do with them. Upon being named Ren, she imprints upon him as her "Master" and serves as his personal "Slave," leaving him with a "DearS" who wants to remain with him no matter what and bringing his ordinary, alien-free days to an end.