The series from which Shin Megami Tensei emerged from, otherwise known as Digital Devil Story.
The original series of books consists of Digital Devil Story: Megami Tensei (Goddess Reincarnation), Digital Devil Story 2: Mato no Senshi (Warrior of the Demon City), and Digital Devil Story 3: Tensei no Shuuen (Demise of the Reincarnation). The story of the book series would see high school student Nakajima Akemi develop a computer program, which would summon demons from another realm. The program would go out of control and unleash a horde lead by Lucifer, whom Akemi has to defeat with the help of Shirasagi Yumiko, a transfer student that became interested in him and is the titular Megami Tensei. By the end of the third book, Akemi and Yumiko lose against Lucifer.
The first Digital Devil Story would spawn an OVA adaptation, and two different games - one developed by Telenet for Japanese computers, and the far more famous Atlus game for the original Famicom. The follow-up of the Atlus game, Megami Tensei II, would diverge from the books substantially and ultimately lead to Shin Megami Tensei I. References to it can still be found in later Megaten games.
