Soichiro Yagami was returning home from a long day's work at the station. As he inserted his key into the lock, he felt something was slightly amiss. The tongue of the lock clicked as he turned his key. The door swung open with a slight squeaking noise. He had wanted to oil its hinges for some time, he remembered. As he stepped in, he noticed that nobody was in the living room or kitchen. For some reason that he could not comprehend, steely terror clawed at his very heart. He felt incredibly tense, and his hand almost reflexively felt for his revolver. He checked himself. No. He shouldn't be paranoid. What if it was just a little surprise Sachiko and the kids had set up for him? Their anniversary was next week, after all. Maybe they were all upstairs, planning out a vacation or something.
A vacation. That sounded nice. He had been very busy for the last few weeks. There had been a very gruesome murder case just recently. A kid had stabbed his entire family to death. He was just 18. A year older than Light. It greatly pained him. He had been barely able to sleep for the last week or so.
He took a deep breath, trying to calm his heart's restless thudding beat. He noted that the lights were on, vegetables lay half-sliced on the cutting boards, Sayu's homework was open on the dining room table, Light's sneakers stuffed into the shoe rack hurriedly. As if they had all been there just a minute ago. He climbed upstairs towards the bedrooms, his hand on his revolver's handle, feeling the solid, comforting, cool steel. Somehow, this contraption of metal made him feel safer.
He opened the door of his and Sachiko's bedroom.

Soichiro would never be able to wipe the image that met him from his memory.
He saw Sachiko's body laying on the bed, her neck violently sliced open. Blood all over her gentle features, which were contorted into a final grimace of pain. The red fluid was all over the floor. It had stained the sheets, the walls, the carpet. He leaned on the door frame to steady himself. He gasped in and out, in and out, trying to regain his mental facilities from the shock he had just experienced.
Another thought flashed through his mind.
"Sayu!" He screamed.
As he burst into his teenaged daughter's room, he was horrified to find Sayu with her head laying on her laptop's keyboard, headphones still plugged in, blood all over the screen and desk and floor and everywhere, everywhere, everywhere...Dripping from her neck, to her fingertips, pooling on the ground.
The only one left was Light.
Soichiro tackled the door of his only son's room open, as it was locked tight.
Light was sitting on the edge of his bed, reading a newspaper. When Soichiro smashed his way in, he looked up calmly, indifferent to his father's forced entrance.
"Light...you're alive!" Soichiro exclaimed, with a confused and pained look in his eyes.
"Of course I am. Why so serious?"
"What do you mean, why so serious? Sachiko and Sayu are dead!" he screamed.
"Oh...crying shame." He turned slightly more attention to Soichiro, whose emotions were a muddy puddle of rain mixing with blood and tears. "Anyway, too bad you weren't here to see the show. It was quite fun." At this, Light put down his newspaper, and Soichiro recoiled at seeing Light's black shirt splattered across the front with red.
"You...killed them? Light...How..." Soichiro stepped back, his mind refusing to accept what he was seeing.
"With a kitchen knife, of course. How else?"
As he said this, he stood up and picked something up from besides the bed. It was a long, sharp, kitchen knife, drenched in sticky, strawberry-red blood.
Light walked slowly towards Soichiro, who had drawn his gun. Soichiro primed the round. His finger was on the trigger, ready to fire.
"You wouldn't do it, would you, father? Shoot your only son? The apple of your eye? Your pride and joy?" Light taunted.

Soichiro wavered. His deep brown pools of eyes were filled with tears. Tears of pain. Horror. Love. Hatred. Shock. Betrayal. Treachery.

Light struck, plunging the blade deep into Soichiro's chest.

Soichiro felt the icy steel run a path directly through his heart. His eyes met Light's, and he thought, for a moment, just a moment, a fraction of an eternity, he saw the tiniest twinge of regret in his son's eyes.
Soichiro's mouth opened in a silent scream.

As he staggered backwards in agonizing pain, he clutched at his chest, where Light's blade had cut into him. He dropped his revolver, and fell onto his knees, still clutching at his own bleeding heart. As if his own hands could hold the blood in. Soichiro fell onto his back, blood spattering his glasses. He saw, through the darkness of his vision, Light grinning and licking his own father's warm, fresh blood off the blade.
As if it were strawberry jam, Soichiro thought.
Light looked at Soichiro, and, crouching, leaned in close to him. That grin was still plastered all over Light's face He whispered gently, almost lovingly, into his father's right ear.
"Good night...father."
He smiled, and kissed Soichiro lightly on his cheek. Like Soichiro used to kiss Light when he was a little boy, as he tucked him into bed. Soichiro's eyes spoke volumes about his feelings. Now, all they said was sorrow. That was all they told of. Sorrow. The pain and sadness of a man betrayed by the one whom he trusted and loved the most.
A single tear rolled from Soichiro's eye. It dripped into the pool of warm red blood that spilled forth from his broken heart. The dying man groaned his last belabored word.
"Why?"
Soichiro Yagami's eyes closed for the last time.
Light Yagami's grin became wider.

"Because I was bored."