"...Welcome to my world. Until yesterday, I was extremely talented, but still ultimately human. But now, I am the ruler of the Demon World having received the omniscient, omnipotent power.The denizens of the Demon World call me the Deity Emperor. You have been blessed with a once in a lifetime privilege to behold me. Your fate, whether you live or die, is now entirely up to me. You'd best put on a good show."
—Hazama at the start of if...
Ideo Hazama is the main antagonist of Shin Megami Tensei: if..., proclaiming himself as Deity Emperor (魔神皇?, lit. "Demon God Emperor").
Abused by fellow schoolmates, betrayed by his first and only love, and comforted only by the school nurse, Ideo Hazama is a student of Karukozaka High School. The corruption of the abuse from his schoolmates forced his mind to become warped. He tries to summon a demon within the Gym (which explains why the gym has a summoning circle within it), but the summon goes out of control and opens a portal leading to the world of demons known as the Expanse, where Hazama would eventually come to rule as Deity Emperor. The following day, the school is sucked into the Expanse leading to the intro of the game. He first appears appearing as a vision to the protagonist, and later reappears several times as a statue, informing her on what world she is in, and how said world applies to humanity. When the protagonist and her ally make their way through the Expanse, they face him directly within an abandoned version of the school. In Reiko and Yumi's path, he reveals his demon form and attacks them, while in Charlie's path, he simply lets him and the protagonist leave, as their selfish goals do not conflict with his plans.
In Reiko's route after the Deity Emperor is defeated, the Ring of Deliverance shines, allowing the protagonist and their allies to enter his mind. While they are traveling through his mind, they see his memories and learn of his motivation for his actions. When they reach the center of his mind, Hazama scolds them and transforms into the manifestation of his warped mind; a giant fetus demon with Hazama acting as the right eye, ankle-deep. After defeating Hazama in this form he expresses his hate for losing, turns into a younger version of himself, and states the protagonist is picking on him like everyone else before starting to cry. Reiko comforts him and he returns to his normal age. She promises that she will not leave him anymore, and the protagonist is warped out of the room. Reiko informs them that Hazama's warped mind is returning to normal, and that she cannot stay and must leave. As she leaves, Reiko tells that Hazama was originally a kind person, but there wasn't the least bit of love from the people around him. She thanks them for allowing her to save Hazama and forces her to release her demon companions. Afterwards, the school returns to normal. The nurse reveals that Hazama confided what was on his mind to her, and that she should have listened to him. Hazama and Reiko are never seen again.
In this spin-off manga based on the original if... manga, Hazama lives on through a connection with his sister Reiko. After the apocalypse, he is reincarnated and builds a base within the Tokyo Metropolitan Government Building.
Hazama is a Demon Trader who shows up in the Pet Shop, trading certain races of demons for money, which may seem useless or useful depending on the player's situation, and information on the Hero and General demons.
He is Reiko's brother. However, his mother left him when he was young and took Reiko with her, hence why they have different surnames.
The nurse is the only person within the school other than Reiko and the protagonist near the end of the game. It is most likely because she was the only one to comfort him during his abuse from fellow schoolmates.
His clothing is available as a promotional item for male characters in Shin Megami Tensei IMAGINE. When the Hazama-themed Ruler's Gloves are equipped, players assume his stance.
His family name, Hazama, literally means "threshold", an intentional choice according to story-writer Ryutaro Ito, as he is the "threshold between demon and human".