|Also known as||Atsuya Tsuzuki|
|First Appearance||Majin Tensei|
The Protagonist is the main character of Majin Tensei.
- Majin Tensei: Protagonist
- Majin Tensei: The True Remembrance: Protagonist as Atsuya Tsuzuki (都築敦也, Tsuzuki Atsuya)
- Majin Tensei II: Spiral Nemesis: Mentioned
Unlike the majority of Shin Megami Tensei Protagonists, he is not silent. While not many details of his past are given, his late father was a computer engineer, inspiring him into the profession of computer communication, and that he was born in the district of D-03 in Neider Tokyo. At the time of the game, he is 17 years old.
Before the events of Majin Tensei, he had been using computer communication to collect information about the rumors of the demons and the damage of the earthquakes, wanting to verify if they were true. At the beginning of Majin Tensei, by chance, a mysterious person known as TAKEUCHI had sent him the Demon Summoning Program on his COMP.
In the late 1990s, ethnic battles around the world result in a large amount of deaths and a large portion of the world being closed off. Decades later, in 202X, a boy living in Neider Tokyo in the area D-03 suddenly receives a mysterious Demon Summoning Program on his COMP from someone called TAKEUCHI, with demons appearing immediately after. After fighting his way to a mysterious building, he finds a young woman in cryogenic sleep, who decides to join him. There are 3 possible endings: a bad ending, a normal ending, and the best ending.
The bad ending is received if the protagonist kills any demon during chapter 51. This is the only way to get that ending, and is presumably gotten due to the ethics of killing non-hostile, extremely weak demons.
The normal ending is received if the protagonist doesn't kill any demons in chapter 51, but doesn't fulfill any of the requirements for the best ending.
The best ending is received by not killing any demons in chapter 51, and then managing to fulfill the many requirements for obtaining this ending (e.g., letting the protagonist sacrifice himself to obtain the Hinokagutsuchi's power rather than the Heroine or a demon, not killing Lucifer).
Majin Tensei II: Spiral Nemesis
Although not being seen, the Protagonist, along with the Heroine is mentioned by Lucifer in the Neutral route as Masakiyo Ogiwara's true parents who saved the human world during a crisis, and left their child with the Ogiwara family.