The Root of TYPE-MOON
Nasu wrote the original script for Mahou Tsukai no Yoru in the winter of 1996, and only showed it to a few close friends before moving on to other projects after the novel was rejected by several competitions due to it being over the page limit. Mahou Tsukai no Yoru was Nasu's first novel, and marks the beginning of Nasu's fictional worldview.
In early 2008, a game version of Mahou Tsukai no Yoru was announced along with Girls' Work and a Tsukihime remake in the first issue of TYPE-MOON Ace. TYPE-MOON chose to take a different direction for the new game, unlike Tsukihime and Fate/stay night, Mahou Tsukai no Yoru will be all-age and its art is handled by Koyoma. Nasu mentioned in an interview in 2008 that he wanted the game to be a "visual story" rather than a "visual novel game." Later announcements revealed that the game will not have voice actors or branching story routes.
Mahou Tsukai no Yoru was set to release sometime in 2009. After several delays, the game received a September 2010 release date. In September, however, TYPE-MOON pushed back the release date to 2010 winter, and later TBA 2011. A demo of the game was released with TYPE-MOON Ace issue 7, along with a confirmed release date of April 12, 2012.
The Unpublished Novel
The original Mahou Tsukai no Yoru was written by Nasu in the winter of 1996. According to Nasu, the novel was written with "to show to people other than my close friends" in mind, and was inspired by the first episode of Neon Genesis Evangelion. Nasu gave up submitting the work to a competition by Fujimi Shobo after his inability to keep the page count down by 350. In the end, he only printed less than 5 copies of the original draft. Some of the characters from the original story were drawn by Takeuchi for his old personal website.
TYPE-MOON released a material book in 2006 called Character material. According to the book, the story of Mahou Tsukai no Yoru takes place in Masaki Town approximately 10 years before the events in Tsukihime, where Aoko abruptly entered the world of magecraft after her grandfather suddenly decided to have Aoko become Azaki family's successor. Since then, Aoko has been living and training with Alice as a magus-in-training under the guise of doing part-time work.
The theme of defending the city against enemies through magic battles and three main characters living in the same house was later used in Tsukihime and Fate/stay night. While no one has seen the original draft, rumor has it that at one point in the story, Aoko took Soujuro home on a leash. Also, it was said that Touko and Aoko's rivalry was mention in the story, and during the final battle between the two, Touko lost and was cursed by Aoko and Alice so she could never return to Masaki.
It's worth noting that after the success of Tsukihime, many fans began searching for Nasu's old works, and many searching for Mahou Tsukai no Yoru came across the doujin novel by Akizuki Osamu. According to Akizuki, he has never seen the original script, and the fanfiction came purely from his own imagination.