During the fitting sessions before Eri’s trial, Nao had everyone with a fitting session, besides Ren and Masaaki, who had a session before the body discovery announcement (Sekai, Hanami, Tim, Caren, Sahirah, Hoshi, Eri, Eisuke, and Kukuru) write a positive message that would be given to someone who could use some help.
When Nao finally finds some alone time in his suite room on Floor C, he begins writing an unsigned message. He copies the handwriting of Sahirah that he’d gathered during the fitting sessions by tracing over the letters she wrote, arranging the letters to form a message asking the receiver of the new message to meet at the Ski Shop at midnight. This is done twice so that two fake messages are made.
Nao also writes suicide notes dedicated to every person that was still alive, with his own handwriting and pen. After writing everything, he hides all of the papers under his bed for future use. Monokuma ferrets them away shortly afterwards.
Later during the day, Nao slips the positive messages from everyone he’d asked to write under Azaki’s door, effectively getting them off of himself and onto someone else.
The next day, at 9:24, Nao arrives at Floor A, where he takes an icicle from the Freezer and hides it on the Floor A-Floor B lift. He also makes a mess of the Freezer by scattering the empty containers over the floor. Another icicle is broken off of its base and then broken into two and left at the Freezer. Right after, he goes to the Cafe and takes a knife, hiding it up his sleeve. By the time he arrives at Floor C, it is about 10 AM. He hides the knife and icicle under the snow outside the Ski Shop’s broken window. After that, he goes to his room and pockets his two fake Sahirah messages.
At 10:43 PM, Nao sneaks into the empty Cafe and takes a blender, transporting it to the snow outside Floor C where he hides it with the knife and icicle. He also leaves the blue pen he used to write the fake messages under one of the Cafe tables.
At 12 AM, officially the next day, it is time to continue the plan. Nao leaves one of the messages, crumpled up, in one of the Floor C male bathroom’s stalls. He then visits his soon-to-be grave, the Ski Shop. He begins making a mess of the room, throwing some jackets on the floor, as well as other ski accessories. A few of the gifts are also scattered about. Nao takes the blender over to the male bathroom, fills it with hot water, and carries it over to the ski shop. He throws a little of the water on one of the jackets and sets the blender down.
Nao produces his notebook and pen and begins writing as an afterthought. He also slips the remaining fake message into his notebook and places it on the floor.
Nao takes a ski pole, and after several moments of contemplation and preparation, stabs into his left hand. Thankfully, he muffles his scream by having his face buried in one of the ski jackets. He dips the sharp end of the pole into the blender, cleaning it of some of the blood (but some residue still remained), and he throws it out the window as far as he can. Nao takes the knife and lays it on the floor beside him. He also takes the icicle and places it by the knife. Imagining what was about to happen is enough to make him turn around and vomit. It takes a minute to recover, and when he does, he takes the blender and drops all of the hot water on himself. He then rolls the blender away.
Finally, Nao takes the icicle and stabs himself in the chest after taking a moment to steel himself. He lets out a small yelp before falling on his side. The hot water on him makes the icicle melt more quickly, and also allows the cold water from the icicle to blend in with the hot water. It takes little time for him to die with a hole through his aorta.
Some four hours later, Masaaki and Kukuru meet in the Pantry. A conversation leads to Masaaki falling into a brutal rage and killing her with the closest heavy object, a bulk container of dry rice.
He panics and drags her body to the Freezer, where he tries to stitch up her head wound with the first-aid kit, but to no avail. She is already dead. Entering another rage, he goes back into the pantry and destroys the entire room. A sharp edge from a falling shelf cuts his right thigh.
There is already a blood trail from the pantry to the freezer from Kukuru’s wound. There is now a thinner blood trail leading wherever Masaaki goes now. In addition, he’s limping now and has to use the wall as support; this leaves smeared, bloody hand prints.
His destructive rampage continues into the Barracks. Anything he can find is destroyed, and the room is littered with broken items.
He returns to Kukuru’s side when he’s done and decides to stab her multiple times with a knife from the Pantry, though the wounds are not deep. He gets mad about how the wounds look and decides to cover them with her own clothing.
The final thing he does is shower, getting blood traces all over the washroom.
Though ??? does not find Nao’s corpse before the other students, ??? does uncover Kukuru’s. Hurrying to the Pantry, ??? finds a knife that matches the one at the scene of Kukuru’s body, complete with a bloodstain on the blade. To make a matching wound, ??? sneaks up on Azaki and stabs him with the other knife, fleeing before ??? can be found.
As a final touch, ??? smears a small amount of Azaki’s own blood onto the outside of his door handle. ??? then washes the bloody knife and returns to the crowd, slipping the blade back into the Pantry during the investigation.
