Project Yggdrasil was a combined effort by both Devils and Gods to create a sentient being with an enormous amount of magical energy. The project was an attempt to have power over life and death, the one thing magic couldn't do. Three attempts were made in all, with only the third one successful.
First Attempt
The first attempt started about 20 years before the events of Shuffle!. It included an ordinary female Devil, who was simply injected with a larg
Ama was the first attempt
e amount of power. After a while, the power went out of control, annihilating the entire facility. The test subject was considered dead. It could of been a disaster in both life count and diplomatic relations between the races, but this was mostly avoided by the project being top secret, and the facility being remote.
Unknown to all but the test subject, she didn't die. Instead, her power created a rift between the world of the Devils and Earth, hurling her there. After some time, she was found by a man who took her in. Eventually, she had a daughter, Asa Shigure. She went under the name of Ama Shigure, the origin of her first name was never specified, while the last name was probably adopted from her husband.
Second Attempt
For the second attempt, it was decided that a body was needed which could handle large amounts of energy. The choice fell upon Nerine,
Lycoris is the one who met Rin on a visit to the Human world
daughter of King of Devils. A clone of Nerine was created, named Lycoris. While initially successful, the body eventually deteriorated because of the large amount of energy, as well as imperfections in the cloning technology. Lycoris' final act was to merge her being with Nerine in order to save her from an incurable disease. This had a side effect of also transferring over some of Lycoris' emotions and desires (as well as her singing talent).
Third Attempt
See also: Primula.
The third attempt started well before Lycoris died, when her decay became obvious. It involved creating a suitable body literally from nothing, a homunculus in the true sense of the word. It took many tries and many failures; The King of Gods called it a miracle which could never be repeated. The new life form, created about 10 years before the events of Shuffle!, was named Primula. She had no family, and had little contact with other beings. The exception was Lycoris, whom she considered an older sister. Before Lycoris disappeared, she gave Primula her cat doll to remember her by. That doll became her most precious possession.
Primula was the last and only sucessful attempt.
Somehow, she made it to the world of Humans, in order to find Rin Tsuchimi about whom she heard much from Lycoris. After that, she expressed a wish to live with Rin, which was granted.
Since Primula's powers were considered to be tied to her emotions, for a long time, she didn't display them at all (except around Lycoris). During the events of Shuffle!, she learns to display them, especially if she is Rin's love interest. In the anime, her emotions cause her to lose control of her powers, leading to a prolonged stay under supervision of Devil medics. A catastrophic release of energy is narrowly avoided by the brief reappearance of Lycoris.
In the anime, there is an attempt to take Primula back to the world of the Devils when she learns to control her powers. This causes objections from many of the characters, ending up in the compromise of transferring the project over to Earth.
Trivia
- The name of the project is never mentioned in the visual novel, only the anime. The name alludes to Yggdrasil, the world tree of Norse mythology, which connects together all the parts of Creation.
- All three test subjects have purple eyes, including Lycoris, who is a clone of the red-eyed Nerine. The similarity is only remarked upon once in the visual novel (about Lycoris and Primula alone), and never in the anime. Asa Shigure seems to have inherited those eyes along with the magical power.