The 'killer' is revealed

                                    

                                          
«Makoto Naegi's Perspective»
We all stare at Byakuya, illuminated by the gleaming light of the elevator. He- or she, now we knew more about her- was bloody and still dripping aqua blood.
"HOW ARE YOU ALIVE!" Screeches Monokuma, leaping up from his gilded throne. 
"Wait, if no one is dead, there's no trial, right?" Yells Mondo. Chihiro looks up from her sobbing, petrified. 
"W-what about our secrets?" She cries.
Monokuma growls, slashing the poster of Byakuya with pointed claws. "I REALLY WANTED TO EXECUTE SOMEONE!!! EUGH!!!!" He hurls the throne into the wall with unnatural strength. "NOBODY IS LEAVING THIS ROOM UNTIL THE PATHETIC SWINE WHO TRIED TO KILL SOMEONE AND FAILED OWNS UP!"
                          
«Kyoko Kirigiri's perspective»
"I'm sorry!" Sobs Chihiro, shoulders trembling. "I did it!"
"Chihiro, calm down. It's probably just a misunder-" Makoto begins, but she interrupts him.
"No! Someone- someone told me-" She splutters "someone told me to kill Byakuya, cause if I did it- it would be confusing-"
"Why?" Queries Sayaka, but however hard she tries, Chihiro can't force the words out. 
"C-C-Ce"
"SHUT UP YOU SWINE!"
My neck almost snaps as I twist around to stare at Celestia. Her ebony hair drills twist in fury, her eyes alight with fury. 
The sudden burst of fury changes chihiro. She stands up taller, balling her gloved hands into fists. 
"Celestia told me to kill Byakuya," she yells "But I only agreed because I was going to trick her!"
"I KNEW IT!" Screams Celestia. Her demur personality has snapped, revealing the real Celestia Ludenberg- though I'm starting to doubt this.
"I'm so confused. Why the hell don't we ASK the person who was murdered?" Yells Mondo.
"I didn't see their face," answered Byakuya, wiping blood of her glasses surreptitiously, "But I could tell it was a girl who was shorter than me."
 Celeste tugs at her hair, "Are you STUPID! It's obviously Chihiro!" 
"She just said he didn't!" Yells Aoi.
"HOW can you trust him. He's  been lying all this time about his gender! SHE is a a BOY!" Shrieks Celestia.
"NO! I don't believe you!" Splutters Ishimaru, but Chihiro has paled. She nods determinedly. 
"I am a boy. I'm sorry for lying, but- I didn't want to get bullied for being weak!" Chihiro looks at Mondo with huge, pleading eyes. "But I wanted to change! I thought this was my chance to be brave! So I agreed to Celestia's plan, but I went and told Byakuya!" He wipes his eyes "I was too late though. She was already dead!" 
Everyone turns to Celestia:She looks deranged, her hair sticking up manically. She laughs fearfully, "You- you think I did it?" She whispers. "Fine. EXECUTE me then! I'd have  gladly killed all of you to get out of here!"
Monokuma shakes his head. 
"No execution today! But there will be a punishment! For all of you!"