The man winced as the blade tightened against his flesh.
"How could you!?" Sanji shouted blinking back his tears.
"She was only a girl, she was only fifteen."
"Sanji-kun," Ace whispered trying to draw his neck away from the blade.
"Don't you dare call me that!" Sanji's knuckles turned white with the strain of his grip around the handle of the knife.
The cook's other hand lifted to wipe away the tears streaming down his face.
"Give me one reason I shouldn't kill you right now Ace," Sanji growled, the hand he used to wipe his face pinning Ace to the ground once again.
"B-because I love you Sanji and I'd never do anything to try and hurt you," the man under Sanji lifted his hand to stroke the cook's cheek. "Please Sanji I need you."
Sanji removed the blade from the man's neck long enough for him to punch Ace across the face. For Sanji punching someone was a big deal. In combat Sanji never used his hands, they were too precious. If something happened to his hands he wouldn't be able to cook again.
Sanji's punch hit Ace hard in the jaw and he spat out some blood as a result of it. Ace's eyes were misty and Sanji could see he was on the verge of tears, not that he much cared.
"It's too late for that. You killed Mai, you killed my sister!"
At that moment several Marines burst into the room and dragged Sanji away from Ace whilst they evaluated the situation. Mai's body was taken away despite the fight Sanji put up. Ace was to be put into prison until his court case a few days later.
After finding out that Ace had borderline personality disorder, the court came to the verdict that he be sent to the institute of Impel Down.
Following the events of Mai's death, Sanji spiraled into depression. A depression filled with haunting nightmares, sleepless night, self-harm, starvation and alcohol. He barely spoke when he returned back to school. The cook had even considered suicide more than once, anything for him was better than the pain and betrayal he was feeling.
Sanji didn't move from his crouching position on the floor. He didn't even move when Franky picked him up and took him back to the girls' dorm. He didn't move when the door was shut behind the man as he returned back to his nakama. The cook's fists balled around the sheets of the bed as he cried himself to sleep. _
"Luffy you must know something?" Nami said once Franky had taken his seat at the table. "Ace is your brother."
"I know who Mai is and why she's dead and I know what Ace did. I know everything about that summer," the head of the house said raking a hand through his raven black hair.
"Well are you going to tell us?" Usopp asked.
The straw-hat boy looked away from his nakama.
"I don't know if I should, I mean Sanji doesn't even know that I know."
Zoro slammed his hands onto the table startling the rest of them.
"Well you better speak up! I'm tired of not being able to help the ones that I love, so you better tell us everything there is to know."