What would happen if Tsukasa and Ryuji had parted ways in chapter 34:
Ryuji's heart would break as soon as he realised she meant it. He quits school to focus on Kuryugumi. When he was 18, he would marry Asago and make her his seisai. Horribly cruel to everyone he meets, he had reverted to how he was before he and Tsukasa became friends. Kamo-San watches in horror as Ryuji grows up to be a cold-hearted sandaime, no trace of happiness left before he reaches eighteen. He has one child, a daughter named Kanako, that he cannot bring himself to love because her mother is Asago. He and Asago drift further and further apart, and she has lovers that all of Kuryugumi know about. Ryuji tries to focus on life, but he can't stop thinking about Tsukasa, and sinks further and further into his black hole of depression.
Tsukasa finds another way to repay the debt, and has repayed it all by her high school graduation. She makes it into a police academy on a scholarship, and with Akira's support, but must enter as a girl. Akira confesses his love for her when she graduates and is instantly put in GRAVE. They marry two years later and end up having three sons that love fighting just as much as she does. She achieved her dream of being a cop, she has a loving family and a comfortable home, but something is missing. A hole in her heart the size of Ryuji. Her middle son(kouki) is the same age as Ryuji's daughter, and they become friends when they sit next to each other in class in year 9, when they are fourteen. Kanako knows from Kamo-San the previous relationship between Ryuji and Tsukasa, and asks Kouki not to tell his parents that they know each other. Her last name is different and her parents never visit school so that she can have the peaceful school life that Ryuji could never have. When Tsukasa is nearing retirement, she is sent goes on one last assignment. She ends up bursting into a warehouse with two men inside. Ryuji and the son of Hizaki. When she runs into the room, Ryuji's gun flies up from habit, and she is shot in the chest by Ryuji.
Ryuji, who had thought it was Hizaki's kumin in the doorway, shoots Tsukasa without looking. When he turns to look, he sees his childhood love with his bullet lodged in her chest and blood from the wound coating her body. A strangled gasp tears itself from his throat and he falls to his knees, his mind wheeling. He realises that he never stopped loving her, something he has been denying to himself for years. He runs towards her, eyes wide with horror, horror that she was dying, horror that he had caused it, and horror that nothing could be done about it. He has just reached her when a bang echoes throughout the empty warehouse. A bullet goes straight through his chest and embeds itself in the floor. He tumbles forwards, his eyes never leaving Tsukasa's nearly dead body on the floor in front of him. He lands on her, his eyes wide, face pale, chest stained with blood. If he has to die, this is how he wants to go, the woman he loves with him. He can't even feel the pain anymore. Her eyes are still open, and he can see that she is still alive. He whispers her name and her eyes flicker towards him. "I love you, I always have" he whispers so only she can hear, and she does. It's the last thing she hears as her vision goes black and her heartbeat slows to a stop. The words she was about to say rest unspoken on her icy lips. "I love you too". But Ryuji knows. He dies with a smile.
Hizaki walks away, his job done. Ryuji isn't a threat anymore. He doesn't know who the girl is, but he can tell that she was someone Ryuji treasured. He throws down the gun he used to kill Ryuji as he leaves the warehouse. Sirens come tearing down the street as the police arrive. There is not phong they can do now. Akira runs into the building to see his wife lying motionless and bloody on the hard floor, a man's body lying on top of hers. He has to make sure it's her, so he carefully approaches the bodies and rolls the man off her. The first thing he notices is the man's face. He could never forget that face. Shirogami Ryuji. But his eyes quickly dart down to the woman lying on the ground. It's Tsukasa all right. He checks futilely for a pulse, ignoring Ryuji. The other officers come running in, guns in hand, but they stop when they see the scene in front of them. A member of GRAVE crouched sobbing in front of his wife's body, the body of Shirogami Ryuji lying next to him. (Kanako and Kouki are in their last year of high school and are dating) Kanako and Kouki are sitting in class. Suddenly, a tv lowers from the ceiling and the news turns on. The reporter is at the warehouse, standing outside it. Their phones both ring, and they answer fearfully, because nobody ever calls them. Kanako hears the news from her mother as Kouki hears from his father while every other person in the class watches the screen ands listens to the news report. Their hands clutch each other's for comfort, and when they hang up they instantly rise from their seats, tears flowing from their eyes. Before the teacher can protest, they have left the room, hands still clasped tightly together, their eyes looking everywhere but nowhere. They hear footsteps behind them, so they run, still bound together by their hands. They reach the front gates as two cars pull up out the front. From one car steps Akira, and from the other is Asago. They let go of each other's hand but it is too late. The parents have seen. The parents lock eyes and instantly know. The arguments fly back and forth, each child trying to stop their parent from fighting, but neither succeeding. Kanako eventually pulls Asago into their car, and Kouki does the same. The two cars drive away with a child in each back seat, staring forlornly out the window at the other car. The two know that they will never be able to see each other again.