Ao Oni Version 1.0 (青鬼 1.1 Ao Oni 1.1 ) was the first version of the game. The only official release was in Japanese. It has the most characters out of all versions and the characters who appear in later versions (Hiroshi, Takeshi and Takuro have different personalities. In addition, Mika has been renamed to Megumi).
WARNING: This page may contain spoilers or solutions to puzzles. Read further at your own risk!
The game starts off as Hiroshi and his best friend, Kazuya, are walking home from school, discussing about a new game that Kazuya bought until they accidentally bump into Takuro and his gang: Megumi, Takeshi, and Ryota (who resembles Hiroshi in later versions). Takuro forces Hiroshi and Kazuya to accompany them to a haunted mansion located on the outskirts of town.
The six arrive in front of the mansion and enter. A while later, a sound of a plate being shattered is heard and Hiroshi volunteers to investigate while the rest wait. Searching in the kitchen, the door behind Hiroshi opens, and the scene cuts to the five waiting for his return. After receiving payment from Kazuya, Takuro heads to the entrance door and tries to open it to leave, but it's locked somehow. While everyone is in complete shock, Megumi notices a figure approaching from her side and tries to identify it. The mysterious figure's point of view suggests it's the oni itself, slowly walking closer to Megumi and eventually charging at them. The scene turns to Hiroshi at the time the door behind him opens, a white cat comes out and dashes away after seeing him. He then goes back to tell his friends it was just a shattered plate, but sees they are not there. Hiroshi tries to open the entrance door, thinking that they left the mansion while he investigated. After he tries to break the door with force, he realizes he is stuck inside the mansion and tries to find a way out.
Moving to the bathroom area, he notices a figure moving inside of the bathroom. He tries to open the door but it's locked. Hiroshi then finds Takeshi on the second floor shivering in fear inside a closet, Hiroshi asks whether he knows where the others are but the only response he got was Takeshi's teeth chattering. Leaving him be, Hiroshi explores around the mansion a bit more until he comes back to check up on Takeshi but notices that he's gone from the closet. Hiroshi goes back down to the bathroom on the first floor to discover it's now unlocked. He drains the bathtub and jumps back in fear as Ryota's dead body is lying in the tub. He then notices a key leading to the library room in the dead body's hand. After unlocking the library room, the oni is seen in the corner of the screen. Feeling a bit uncomfortable, Hiroshi proceeds with caution and notices another key on the table to a room located somewhere on the second floor. Just as he picks up the key, the oni appears in front of Hiroshi and chases him around the mansion.
Hiroshi runs into a bedroom on the second floor and encounters Mika who barricaded herself in. She tells him to lock the door immediately and Hiroshi does so to keep the oni from coming in. With a sigh of relief, Hiroshi asks Mika to join him in escaping the mansion, but she decides to stay inside as long as the monster is still out there. No matter what Hiroshi does to persuade her to come with him, she does not budge so he leaves her alone for the time being.Searching the whole mansion a bit more with some more keys found along the way, Hiroshi finds a room with a cell. He sees another key inside the cell, but feels suspicious, since the oni was not seen for quite a while. So he locks the cell door and grabs the aforementioned item. The oni immediately appears but, since the cell door was locked, Hiroshi was safe. The oni stares at him through the bars then attempts to grab and pry them open with force but doesn't succeed. It looks at Hiroshi once more then leaves the room quietly. Feeling safe, Hiroshi leaves the cell room and the Oni ambushes him. After escaping, Hiroshi enters an archive room full of DVDs and VHSs, but he finds nothing in there. Upon leaving, he finds Takuro and tells him where Mika is, giving him the key to the room she was in. Takuro leaves and Hiroshi follows, however, he is greeted with the oni standing over a dead Takuro and begins chasing him. After escaping, Hiroshi comes back and takes back the key from Takuro's body.
As Hiroshi approaches the door to the basement, he is chased once more. Once safe, Hiroshi climbs down the stairs leading to the basement and finds a room. Upon searching, he picks up a photograph lying atop a desk. The photograph depicts two young boys with a couple who appears to be their parents. After picking up the photograph, he discovers a key underneath it which he pockets. Then he hears the oni slowly approaching and he quickly hides inside a closet, leaving the monster confused. Using the newly found key to unlock a door leading to the underground tunnel, Hiroshi heads deeper inside and eventually finds a rope ladder leading to a way out. He returns back to Mika and she joins him. They both head toward the rope ladder only to see it being eaten by the oni and they flee.
Meanwhile, Kazuya wakes up, finding himself sitting in the corner of a bathroom. He leaves the mansion from the now unlocked front door and later realizes that he originally came here with Hiroshi and Takuro's gang. He questions if they left without him, but he plucks up the courage to check. Kazuya then finds a well leading down into the basement of the mansion. He picks up a rope ladder from a nearby shed, attaches it to the well and climbs down. At this moment, Hiroshi and Mika, while in pursuit, ran back to the basement. They reunite with Kazuya, with the oni still close behind, and the three climb up the rope ladder. They drop the rope ladder to keep the oni from climbing it and Hiroshi peers inside. He watches as the oni clawing up the walls of the underground tunnel with teeth bare. It scares the trio as they flee back to town. Hiroshi knows he couldn't tell anyone about what he saw that day, but he wonders what was the truth behind the mansion. Then he realizes he still has that photograph inside his pocket...
Version 1 featured many glitches. Some include going on stairs via the side of them, and one that wouldn't be patched for multiple games: trapping the Oni, caused by the poor AI of the version. Chases in this version were significantly longer than those of any other version. Also in this game, both Hiroshi and Takeshi had different appearances from the following versions. Most noticeably, Hiroshi had black hair and Takeshi had curly brown-ish hair.
This game has a secret game over that only appeared in this version. To trigger it, after you reunite with Kazuya, you must head to the room where you hid in the closet, the oni won't chase you. It will have vanished, however upon returning to the rope ladder will reveal that the oni had eaten it, giving the Player an instant game over since there is no way to escape besides the ladder.