He is eight-years-old when he first dreams of exploring the depths of space together with Rukia. He is fifteen when Rukia is adopted by the then-Major Kuchiki Byakuya, thus ending whatever dreams he had of exploring space with Rukia. For two years, Renji works to try and better himself, and when he is seventeen, he meets up with a recruiter and enlists in the Gotei Colonial Marine Corps.
He makes it through boot camp, despite the sneers he got from the drill instructors for his long hair and tattoos. Renji proves himself to be a fair leader, and by the time he becomes a Corporal, he is admired by his unit, well-regarded by his Sergeant, and respected by the brass. But at that point, most of his missions had been Earthbound, and whatever space missions he’d had were within the Sol System. He can’t help but wish to go into deep space.
Finally, the opportunity presents itself.
A mission on a deep-space orbital station. It should’ve been simple.
It was pure hell.
The station, Iwashiro, is cold and dark. The shadows seem to move, every noise has Renji on high-alert, and the eventual realization that he is all alone with whatever creatures are on the station strikes him hard.
He is not trained for this kind of a clusterfuck. Within less than 24 hours, his entire unit is dead, having been either taken away by or killed by what can only be described as a black, terrifying vision of every childhood nightmare multiplied by a thousandfold.
And there are multiple of those things. One of them killed the last two survivors of his unit.
He'd heard their screams over the radio, and arrived just in time to find their mangled bodies.
Renji’s whole body hurts. Memories of corpses with holes in their chests flash through his mind. One of those facehugging parasites had attached itself to his Sergeant’s face (he’d killed him with his flamethrower to spare him the horrific fate). Two marines killed by friendly fire. The sounds of agonized groans from within the creatures’ nest ring in his ears.
He doesn’t have much ammo left. His flamethrower is probably down to fumes now, and he’s dangerously low on pulse rifle rounds.
Alarms blare all around him, and warning lights flash blue and yellow. Steam is pouring into the whole station as the systems try to compensate a reactor about to blow. The A.I. mainframe is announcing the time to self-destruction.
“Danger. The emergency destruct system has now been activated. The station will detonate in T-minus 5 minutes.”
He makes eye contact with the creature as it stalks around the corner. The ship is waiting outside the station. The exit to the dry dock is a few steps away.
Renji takes one step back, and the alien hisses and menaces towards him.
Two steps back, and Renji points his flamethrower at the alien. It stops in its tracks.
Three steps back, and he puts his finger on the trigger.
Four steps back, and the alien opens its jaws. Renji’s heart pounds against his chest when he sees the inner mouth slowly extending outwards. It doesn’t immediately go for the kill.
It’s toying with him.
For a moment, Renji is frozen. He closes his eyes.
“You are my lucky star.”
He knows that song. It was from one of those old, old movies that he and Rukia had once seen as children.
Swallowing his nerves, Renji whispers the lyrics to himself.
“You… are… my lucky star…” He tries to keep his voice even. “I saw… you from… afar… two lovely eyes… at me they were… beaming… gleaming…”
He’s not going to die tonight.
“The station will detonate in T-minus: 1 minute.”
Opening his eyes, Renji pulls the trigger. The alien screeches in anger as it is hit with a burst of flames.
He bolts into the chamber and slams the button. The doors slides shut just as the alien lunges for him.
“40… 39… 38… 37…”
Renji runs for it, practically throwing himself through the ship’s open door into safety. The doors slide shut behind him and the ship is speeding away from the station.
They are a good distance away when the station explodes in a gigantic fireball, sending those monsters back to Hell.
Renji slowly sinks to the ground as relief washed over him. “I got you…” he whispers, closing his eyes. “You sons of bitches.”
He has won. He has escaped from those creatures.
When he arrives at Gateway Station, he’s given six months’ leave to recover. Renji returns to Earth to rest and recover while the Corps prepare his papers to transfer him to a new unit.
He may have left Iwashiro, but it sure hasn’t left him.
Renji thinks of Iwashiro too much. Rukia’s offer to stay over and give him company doesn’t help much either.
He has dreams of falling through the stars, of monsters hunting him like prey, of slimy facehugging parasites latching onto his face as he’s cocooned into a wall and unable to break free. He wakes up from the nightmares, screaming and in a cold sweat, and he cannot go back to sleep. His dreams aren’t figments of his imagination; they’re memories. Sometimes, Renji remembers his team, hears their panic, and cries.
Rukia feels helpless every time she hears him cry. She talks to the young General Kuchiki Byakuya, her brother.
The General is stunned when he sees Renji. The young Corporal looks like someone had sucked the vitality right out of him. Byakuya doesn’t know just what Renji went through on that station, but he simply takes one look at him and sends him to Dr. Unohana.
Dr. Unohana is helpful and understanding. She listens to Renji when he tells her about Iwashiro, and gives no judgement or skeptical looks. She doesn’t scold him when he breaks down in tears as he recalls the deaths of his entire unit. She hands him a tissue when he remembers mercy-killing his Sergeant. And she doesn’t allow him to blame himself at all. It's all a mix of guilt and grief, she tells him, and it's perfectly all right to grieve.
The nightmares don’t go away immediately, but Renji continues to see Dr. Unohana for his six months of leave. Little by little, Renji is healing. He’s not the same as he was before, but that’s okay, he tells himself. He will not let those creatures win. He’s a lifer, and he wasn’t going to let them take that away from him.
Four months later, Renji gets new tattoos to commemorate his fallen comrades. It's the same black tribal patterns, and this time, he gets them on his legs.
Towards the end of six months, Renji gets the news: his papers have been accepted by a Sergeant Zaraki Kenpachi. He looks forward to meeting his new unit.
“Thanks for everything,” he tells Rukia, giving her a hug before he heads out.
“Try not to get yourself killed, alright?” Rukia says, giving him a light punch on his shoulder.
Renji promises her he wouldn’t, and heads out after thanking the General for his help. General Kuchiki simply gives him a nod of acknowledgement and wishes him luck.
He heads off to his new unit, feeling much more confident than he has felt in a long time.
He meets his new unit that evening. Sergeant Zaraki Kenpachi is tall, rough, and intimidating, but he’s jovial, passionate, and he’s not afraid to joke around with his men. Renji knows he’s gonna have a good time under his command.
Private First Class Bazzard Black, also known as Bazz-B, greets him by complimenting his eyebrows. Renji’s surprised for a moment, but he smiles.
Then there’s Private First Class Hisagi Shuuhei, who encourages Renji to come over and sit with them. While a little reluctant, Renji eventually sits with them and learns who’s who.
It doesn’t take long before the smiles and laughter become infectious. Renji can’t remember the last time he’s smiled and laughed this much. Probably well before that fateful mission, but that feels like a lifetime ago.
He feels a growing warmth within him, and he hopes that it will last.
He doesn’t know how he managed to survive a catastrophe that felt like a lifetime, but despite his fears, he never stopped fighting. And because of that, Renji survives. His nightmares have not vanished, and it will take a longer time for the guilt to go away, but he thinks he's getting better.
He now has several more years to live and love and laugh and cry. He can live his life to its fullest, and no alien would ever be able to take that away from him or his marines.
If he has to go into the darkness again, so be it. Renji would show no mercy. He'll fight through anything to keep on living, and he will not stop.