OVA Anime
Tetsuwan Birdy
Tsutomu, an average middle school kid busy studying for the final exams to enter high school runs into a man running from someone and gets caught up in the chase. In all the confusion he is accidentally gets killed. Luckily Birdy (an interplanetary agent) knows a way to save him, unfortunately that means joining bodies to become one. So now he is stuck with this officer and along for the ride capturing criminals and saving lives.
(Source: Anime News Network)
Terra Formars: Bugs 2-hen
Adaptation of the Bugs 2 arc of the manga.
In the late 26th century, overpopulation on Earth is reaching the breaking point, and humanity must find new frontiers. The terraforming of Mars has taken centuries but is now complete. The colonization of Mars by humanity is an epoch-making event, but an unintended side effect of the terraforming process unleashes a horror no one could ever have imagined.
After humanity's first manned mission to the Red Planet was lost, a second expedition arrives. The explorers prepare to exterminate the cockroaches that were used to transform the Martian environment. They are shocked to discover that the insects have mutated into giant, aggressive humanoids with one overriding goal — exterminate the humans! But this crew of explorers has each undergone the Bugs Procedure, terrifying experimental surgery designed to make them more than human...
(Source: Viz Media)
Hoozuki no Reitetsu OVA
Three Hoozuki no Reitetsu OVAs will be released in limited editions of volume 17 to 19, releasing February 23, 2015, May 22, 2015, and August 21, 2015, respectively.
Sekaiichi Hatsukoi OVA
Two OVA episodes featuring additional stories.
Episode 0: Ritsu and Takano used to date back in high school, but broke up due to a misunderstanding. This is that story.
Episode 12.5: Hatori and Chiaki go to visit the latter's family. It's really awkward in many, many ways.
(Source: AniList.co)
One Room: another
Unaired episode included with the Blu-ray release, featuring a short snipped of each girl's arc with their clothes replaced with a swimsuit.
Supernatural The Animation
Monsters walk the earth. While some may refute their existence as myths or urban legends, the Winchester brothers—Sam and Dean—know all too well what dangers lurk out there in the dark. Driving around in their 1967 Chevrolet Impala, these brothers have made it their life's mission to destroy anything supernatural that would threaten human lives.
From shapeshifters to werewolves, vampires, ghosts, and even demons, the Winchesters track down and kill every evil being they can find, while also searching for the creature that caused them so much personal tragedy.
(Source: MAL Rewrite)
A-Channel: A-Channel+smile
Following the everyday lives of four high school girls: the flighty Run, the reckless Tooru, the timid Yuuko, and the level-headed Nagi.
Mountain of Pancakes — Kitou-sensei injures her hand during class and has to deal with it while Tooru brings cat Tansan to school with her to meet Yutaka and Miho. Later, the girls decide to get pancakes at a café where Miho happens to be working, facing trouble when Yutaka shows up out of the blue.
A Picture of a Wish — Yuuko catches a cold so the others pay her a visit and help look after her. Later, the girls get together for the New Year's shrine visit.
(Source: Wikipedia)
Kamisama no Inai Nichiyoubi: Kioku
Genshiken Nidaime no Roku
Bundled with the limited edition of the 15th volume of the manga.
Shoujo-tachi wa Kouya wo Mezasu: Iubeki Monokashira
Original anime bonus included with the first print of PC game "Shoujo-tachi wa Kouya o Mezasu".
In the story, Buntarou is a student who wants to be something, but doesn't know what. One day his female classmate Sayuki announces she is working on a bishoujo game. Sayuki scouted him because he wrote a good script for drama club, but Buntarou doesn't know anything about bishoujo games.
(Source: Anime News Network)
Boku wa Imouto ni Koi wo Suru
Yori and his twin sister Iku used to be very close as children but lately Yori has grown colder toward Iku and is always eager to stay away from her. Iku was confused by Yori's attitude. Actually Yori is in love with Iku and that forbidden love is causing Yori sleepless nights since Yori and Iku are sharing the same room with bunk beds. Yori tried to ease his intense desire for Iku by bedding Iku's best friend. He had even applied to attend a boarding school in another city to take him far away from Iku.
Yori lost his resolve to stay quiet about his feelings when Iku started to talk about having a boyfriend and going on dates. Now Yori want to have his little sister and he confessed. Iku loves her big brother and wanted them to stay together, so Iku is willing to anything to keep them together. But Yori wanted to have Iku as a lover, not as a sister loyal to her twin.
(Source: MAL)
Mahou Sensei Negima! Introduction Film
Before the beginning of the series, three OVAs were produced for the sole purpose of introducing the characters. The first two were released on DVD bundled with two drama CDs, with the third being sold separately. It is unknown if these will ever be released outside of Japan.
The first OVA is a re-enactment of the first chapter, where Negi first learns of his job as a teacher and is introduced to the students of Mahora Academy 2-A. It ends with profiles of the Baka Rangers (Asuna, Makie, Yue, Ku Fei and Kaede) as well as Ayaka. Asuna is the only girl in the class that doesn't have romantic feelings for Negi.
The second OVA is a re-enactment of the "love potion" incident of chapter 2, with profiles at the end of Nodoka, Konoka, the cheerleaders (Misa, Madoka, Sakurako) as well as Kazumi.
The third OVA is a re-enactment of chapter 13: Negi's Mahora tour with the Narutaki twins. The tour shows Negi to several of the students (Yuna, Akira, Chao, Satsuki, Satomi, Chizuru, Natsumi, Zazie) as well as others that he ends up missing (Sayo, Evangeline, Chachamaru, Chisame, Misora, Ako). After being chewed out by Haruna for completely skipping her, a final scene introduces Setsuna and Mana, keeping watch from something on campus.
(Source: Wikipedia)
Princess Principal: Crown Handler 2: Revealing Reviews
An anime short included with the Princess Principal: Crown Handler Chapter 2 Blu-ray release.