Saiga is a normal high school student with a gift in mathematics. His daily routine is disrupted when his family gets news that his Father's remains have been discovered—a noted archeologist and researcher who had gone missing while exploring a site many years before. Among his remains were notes and artifacts that needed to be identified by the family near a notable triangular mountain in Japan known as "Japan's pyramid", a place suspected by some to be man-made. A meteor containing a strange robotic lifeform falls from the sky and begins to cause destruction, putting Saiga in danger and causing a mysterious bracelet from his father's research to activate and merge him with an ancient robot burried within the pyramid—a robot the runes describe as Reideen. It is now up to Saiga and guardian Reideen to fight against this unknown alien threat from the sky. (Source: ANN)

A secret unit of the AD Police, known as Branch, specializes in crimes involving humanoid robots called 'Boomers'. Branch officer Buzz must cope with having a Boomer for a partner, while officer Michaelson finds the line between human and robot to be a thin one. Together they serve to protect a world that is slowly deconstructing around them. Set in the Bubblegum Crisis universe. (Source: ANN)

Goro's down on his luck. He keeps losing jobs and has little money. One day he meets a fortune-teller outside of a pet store who predicts that his luck will change. That night three girls appear in his appartment claiming to be his guardian angels. Soon a total of twelve girls appear to help him, each one a reincarnation of a deceased pet once owned by Goro. (Source: ANN)

Maeda has just moved into his new apartment to live by himself. While unpacking, a cute middle school student named Chie Satonaka suddenly appears in his room. She introduces herself as his new landlord, which pleasantly surprises him as he has never seen a landlord so young. His excitement is boosted further when the gorgeous Reiko Shirai, who lives directly next to him, also introduces herself as his new neighbor. Ooyasan wa Shishunki! follows the everyday lives of Maeda and his newfound acquaintances, where each day presents itself as an opportunity for new events to unfold and new bonds to be forged. [Written by MAL Rewrite]