Darker than Black: Season 0 - 5 Episode s
0x1 - Beneath the Fully Bloomed Cherry Blossoms
March 26, 2008
Mayu Otsuka works at the 4th Foreign Affairs Department in the Japanese National Police Agency as a liaison officer with the National Astronomical Observatory of Japan. She wrote a story about a masked man that supposedly seemed to be a dream, but she isn't sure. Hei and his comrades got themselves a new task and are looking for a numeric password with a sample. A contractor took it from the Gate and buried it under a blossom tree. As events unfold, Mayu seems to fall in love with Hei, while Saitou struggles to confess his feelings for Kirihara.
0x2 - Darker than BLACK Gaiden: OVA 1
January 27, 2010
Sometime after the Tokyo Explosion incident, Hei had fought and defeated some Syndicate Contractors and had then fled with Yin to Okinawa. The two posed as newlyweds on their honeymoon, and Hei had tried to find a way out of the country. What began to bother him though was how Yin started acting on her own. The two ended up not leaving by boat because of the ferry ticket lady’s warning about Yin getting seasick, and this led to Hei running into a woman at the hotel who looked exactly like Amber. Yin noticed this as well, and after seeing Hei talking with the woman and later feeling distant from him, Yin had made use of her observation spirit that night. Although Hei had woken up and stopped her from doing anything drastic, Yin saw enough to be able to say that the woman was not Amber but was indeed a Contractor. Yin had tried to suggest that he get out of there, however Hei had just hugged her and vowed not to leave her by herself...
0x3 - Darker than BLACK Gaiden: OVA 2
March 24, 2010
After having a dream where she’s being pulled on by a glowing child-like figure, Yin wakes up to Hei watching over her, and he promises to protect her. The two soon arrive in Hong Kong, and Hei finds a man named Chen to make some fake passports for them so that they can keep running. Yin, however, speaks out because she feels that it’s pointless and suggests attacking their enemies instead. She proposes spreading the rumor that he wants to sell her in order to lure their enemies in, and she believes that they can’t run away while there’s a Doll watching her. All of this plus Yin’s attitude worries Hei, but he decides to have Chen set everything up. While Chen is away, Hei questions why Yin didn’t tell him about the enemy Doll, but she seems not to remember what she said before. She does tell him though that she wants to be with him like this forever. Chen then comes running back because he encountered a dangerous group while spreading the rumors, but Hei is undeterred...
0x4 - Darker than BLACK Gaiden: OVA 3
May 26, 2010
Picking up from last time,the men barging in to help Hei turned out to be Amber’s former Evening Primrose members led by Amagiri. Upon talking to Hei about how books from over fifty years ago predicted the appearance of a girl with the power to change the world and wondering if Amber foresaw all this, Amagiri asks Hei what exactly does he think of Yin. Hei is unable to give an answer...
0x5 - Darker than BLACK Gaiden: OVA 4
July 21, 2010
Claude gives Yin an unknown substance which should make her unstable to fasten her awakening. He calls every secret organization in the world in order to set them up against each other. The Chinese Secret Organization is first, whom Claude sells Yin to. He throws the money out of the window. In the next scene, Hei is seen with the real contractor body of the dog who helps him now because of Claude's irrational actions. They are able to enter into the building, killing contractors in the process. Outside the building, several organizations are fighting each other just as Claude had intended...