It's time to investigate a murder. Upon discovering the body, Monokuma gives Hajime access to the Monokuma File. You can use this to view details concerning the body that would usually come from an autopsy, such as time of death (in this case 11:30 PM) and cause of death (in this case, multiple stab wounds between the throat and abdominal region). Monokuma File #1 becomes the game's first Truth Bullet. You must examine your surroundings and speak to any potential witnesses in order to obtain more Truth Bullets that can be used for the coming trial.
Dining Hall[edit]
Start by examining the duralumin case to the left of the room. The contents of the case have now been exposed, and Hajime finds them odd. Included are a nightstick, pepper spray, an empty case, and a small key that should belong to the other duralumin case. This seems to indicate that the murder weapon wouldn't be found in the other duralumin case, as it has not been opened. But why would Byakuya hide all of these items? Could he have known that something would happen? Hajime receives the Duralumin Case Truth Bullet. Speak to Gundham for another Truth Bullet; he points out that the Gaps in the Floorboard are so wide that he lost an earring through them. While Hajime doesn't think this pertains to the investigation, it's worth noting.
Speak to Mahiru for some clues involving everyone's positions before and during the blackout; Byakuya seems to have been far from the location where his body was found before the blackout, so how did he get there? Examine the air conditioner for another Truth Bullet; the A/C Timer is set to 11:30 PM, the time of Byakuya's death. This could have been the source of the beep heard before the blackout, but what is its significance? Speak to Mikan for her account of the blackout, for which Hajime receives the Embarrassing Pose Truth Bullet. Examine the table at the back for a closer look at the body.
Examine the Night-Vision Goggles for the corresponding Truth Bullet. Nagito points out that they could have been found by any of the students at the Rocketpunch Market, and Hajime wonders if these could have been used by the killer to strike during the blackout. Examine the Knife, which Hajime notes shouldn't have even gotten into the dining hall considering Byakuya patted everyone down for weapons. It also seems to have a glowing paint on its handle. Examine the Bloodstain Under the Table, which seems to have splattered all over the place upon Byakuya's murder. However, there are no drag marks, indicating that Byakuya was not moved after his murder. Examine the body to update Monokuma File #1, as Hajime notes that Byakuya is positioned face-down, as if he was in the middle of attempting something. Examine the glowing tape beneath the table to conclude Hajime's investigation here. Speak to Nagito to finally exit the Dining Hall.
Hallway[edit]
Speak to Ibuki for Ibuki's Account, another Truth Bullet. Using her exceptional hearing, Ibuki is able to discern word-for-word what was said by whom during the blackout. Nagito seems to find what was said by Byakuya especially strange, but for now, turn to the left to find Sonia. She'll point out the existence of the Fire Door in the hall, though Hajime and Nagito have to instruct her on its purpose. Past Sonia is the door to the Kitchen. Enter for some more Truth Bullets.
Kitchen[edit]
Examine the Kitchen Equipment List hanging above the counter for a corresponding Truth Bullet; while Hajime and Nagito don't notice anything peculiar about the list itself, it seems to indicate that the knife did not come from the kitchen, as everything on the list is accounted for. Examine the dishes on the counter for the Party Dishes Truth Bullet. Nagito points out that the only people to actually eat some of the dishes prepared by Teruteru were Akane and Peko, and Teruteru shows a side of himself never seen before. Finally, speak to Teruteru for Teruteru's Account. He claims that the blackout affected not only the Dining Hall, but the Hallway and the Kitchen as well, making it difficult for him to find his way around. He couldn't even use the stove as a light source, since it's powered by electricity. This concludes the examination of the Kitchen, so return to the Hallway. Around the corner, you can find Nagito standing outside the door to the Storage Room. Enter to continue the investigation.
Storage Room[edit]
Examine the irons for the Irons in Storage Room Truth Bullet. Nagito claims that he found all of them powered on initially, so he turned them off to prevent another blackout. Why would three irons be powered on at the same time? Could they have been part of the killer's preparation for murder? Next, examine the laundry hamper. A tablecloth seems to have been hastily stuffed into it, and on the tablecloth is a...bloodstain? The Storage Room Tablecloth is then added as a Truth Bullet, and while Nagito claims it's too dark to be sure, Hajime is insistent that this tablecloth is connected to the murder. These are the only items of interest here, so return to the Hallway and enter the Office to continue.
Office[edit]
Speak to Kazuichi for Kazuichi's Account. Kazuichi seems sure that Peko is the one behind the murder, as he claims to have gone into the Office, where Peko should have been, before the incident and found no sign of her. If what Kazuichi says is true, where could Peko have been? Examine the remote control for the air conditioner in this room to update the A/C Timer Truth Bullet; this A/C timer is also set for 11:30 PM. Examine the duralumin case here and Nagito will suggest opening it. After the deed is done, the pair decides that the murder weapon couldn't have been taken from this case. Finally, speak to Peko. Shortly after beginning the conversation, Peko will suddenly act as if she's ill, and exit the room in a panic. Nagito seems very aware of what's ailing her, but Kazuichi is insistent that she's a suspect. Examine the circuit breaker, located high on the right wall, to conclude the investigation in the Office. Return to the Hallway and exit the Old Building.
Hotel Site[edit]
Upon exiting the Old Building, Hajime and Nagito encounter Gundham and Chiaki. Eventually, you'll obtain a Truth Bullet for Chiaki's Account. Here, she describes a conversation she had with Fuyuhiko, the only student who didn't bother participating in the party. On the way to Byakuya's Cottage, you can speak to Fuyuhiko himself. Use the map to help you find Byakuya's Cottage, and examine the door for a short scene. After the scene, you'll gain access to the interior.
Byakuya's Cottage[edit]
Examine the envelope addressed to Byakuya on the table at the back of the room. It's a letter warning him that the first kill will occur tonight. The letter must be why Byakuya planned the party in the first place. This ominous discovery is the only point of interest pertaining to the case here, but before exiting, make sure to search the left wall; up high is Hidden Monokuma #5. This is the final Hidden Monokuma of the chapter, and exiting Byakuya's Cottage will cut off your access to it for good (unless you replay the entire chapter), so make sure to pick it up before exiting. Return to the Old Building.
Return to the Old Building[edit]
Back in the Hallway of the Old Building, speak to Nekomaru, who has finally made his appearance. Speak to him for Nekomaru's Account, in which he informs Hajime that the bathroom was occupied by someone else when he tried to use it. Who could have been hiding in the bathroom, and for what purpose? Next, enter the Dining Hall and speak to Mahiru for her diagram of everyone's positions. Speak to Mikan for another Truth Bullet in the form of Mikan's Autopsy Results. Mikan tells Hajime that Byakuya's wounds were created by a thin, sharp object around 5 millimeters in diameter. This estimation is odd, as a murder weapon that thin wasn't even present. This should be the last piece of evidence needed before the trial, so an announcement from Monokuma should follow. Head to Monokuma Rock on Central Island, and examine the Monokuma head at the center of the monument after speaking to everyone to activate the "secret entrance." This will take you to the first trial of the game.