40 years ago, a Celebi was being attacked by a Pokemon Hunter. Luckily, a young boy named Sammy saved Celebi. Using its Time Traveling power, Celebi transported himself and Sammy 40 years into the future. There, Ash, Misty, and Brock assist Sammy to the healing lake in the forest so they can heal the wounded Celebi. Unfortunately an evil Team Rocket member, Viscious a.k.a. "The Iron Masked Marauder", tries to capture Celebi using his technology. As Ash and Co. try to get away from Viscious, they also run into Jessie, James, and Meowth, who also want to capture Celebi. Soon it becomes a race against time to get Celebi and Sammy back to the forest before Celebi is caught and is used to destroy the forest and themselves. 

(Source: ANN)

The story revolves around Maya, the daughter of the former Headmaster of Waldstein Academy, and a time traveling agent Fumiaki Uchida. In the year 2012, the world had been invaded by aliens and time travelers were sent back to the year 1999 in order to find and destroy the Nostradamus Key, which Nostradamus Prophecy foretold as what would bring about the apocalypse. The series then turns to the year 1999, where Maya returns to the Academy with the intention of destroying the Academy by superseding her late father's position as the principal. Her plan was interrupted when she meets Fumiaki and learns of the forthcoming destruction. Despite being distrusting towards Fumiaki, they form a pact to look for the Nostradamus Key. In order to find the Nostradamus Key, time agents were provided with specially created cell phones. When a user finds an object of interest, by thinking of destroying it and taking a photo, and if the resulting image is that of a peaceful world, then the subject is the Nostradamus Key. Conversely, if the subject is not the Nostradamus Key, then the photo displays destruction. By using the phone, Maya and Fumiaki investigates occult occurrences as they occur in the town. (Source: Wikipedia)

Episode 0, consisting of two subepisodes: "Sekirei Shindan" (鶺鴒診断) and "Sekirei Yoka" (鶺鴒余暇), of Sekirei: Pure Engagement included on the first DVD/BD volume.

Born and raised in the countryside of Japan, Hinako "Hina" Sakuragi gets anxious easily when she talks to new people—so much so that she resembles a stiff scarecrow. To overcome this, Hina hopes to get involved in theater, inspired by a play she saw during her school's field trip. So, Hina moves into the Hitotose Manor in the bustling city of Tokyo to study at Fujiyama High School, aspiring to join the school's renowned theatre club. But to Hina's dismay, she learns that Fujiyama High's theatre club has been on a lengthy hiatus. Having already come to Tokyo and enrolled in the school, Hina is at a loss for what to do next. Sensing her disappointment and eagerness to learn theatre, Chiaki Hagino, the landlady of Hitotose Manor, encourages Hina to create a troupe with the residents of Hitotose Manor as its members. Hinako Note follows Hina as she begins a new life in Tokyo attending Fujiyama High while learning the ropes of theatre with the support of her friends along the way. [Written by MAL Rewrite]