To celebrate its 40th anniversary, Japanese animation studio Shaft, Inc. presented a "Madogatari" exhibit, combining Puella Magi Madoka Magica and the Monogatari series. The event ran in Tokyo November 27 to December 2, 2015, where it sold out with over 15,000 visitors attending. This is being followed by stops in Osaka December 22-27, then Sapporo February 9-14th. The bombshell out of the opening was a "Madoka concept movie," which was addressed in the January issue of anime magazine Newtype.
Outlining plans, the article said that the four minute, trailer-like short would serve the purpose of an over-the-top production sketch that a new project could be built around. Ideas included developing Madoka as a ballet dancer, Mami as a sort of Battle God, comporable to Romance of the Three Kingdom's Guan Yu, and active new parts for Hitomi and Nagisa.
Previously announced backstory for the short stated that, following the the release of the movies, Magica Quartet (Akiyuki Shinobu, Ume Aoki, Gen Urobuchi, and Shaft) continued to meet leading to Shinbo storyboarding the new concept movie, with animation staff returning for the production, as well as Yuki Kaijura contributing new background music and the cast adding their voices.
Contributing to the concept movie:
Original: Magica Quartet
General director, storyboard: Akiyuki Shinbo
Director: Yukihiro Miyamoto
Altnernate dimension design: Gekidan Inu Curry
Animation director: Junichiro Taniguchi
Sound Director: Yota Tsuruoka
Sound Production: Rakuonsha, Inc.
Music: Yuki Kajiura
Madoka Kaname: Aoi Yūki
Akemi Homura: Chiwa Saito
Tomoe Mami: Kaori Mizuhashi
Sayaka Miki: Eri Kitamura
Sakura Kyoko: Ai Nonaka
Kyubey: Emiri Kato
Momoe Nagisa: Kana Asumi
From the event:
Event's limited etiquette video