Shinkawa Shouichi (新川 昌一), also known as XaXa in SAO was one of the top members in the red guild named “Laughing Coffin.” He was a master of the Extoc Thorn Sword that was bathed in the color of red. XaXa keeps a grudge against Kirito and the front liners that defeated Laughing Coffin in the anti-PK rand. XaXa was also partners with Johnny Black, and served as a combination where they poisoned and killed together.
After his release from Sword Art Online, through the suggestion of his brother Kyouji, he started to play Gun Gale Online. Both looked to another Laughing Coffin member and started to plot a clever plan to kill players in both the virtual world and the real world. Shouichi gets into the Bullet of Bullets competition under the name Sterben to show his true killing ability to the rest of the world. Sterben would stun people with special shells from his L115A3 Silent Assassin sniper rifle and then get up close to shoot them with his Death Gun a 7.62 X 25 handgun.
While he committed the kill in-game, his brother and the other Laughing Coffin member would inject the players in the real world with a syringe that stopped the heart. They had obtained the address by hiding under a Metamaterial Optical Camouflage while they observed the other players type their real addresses during the BoB registration process. His strategies were foiled by Kirito and Sinon, and eventually goes to jail after the incident had passed.
Sterben comes from the German language, it’s also specialized medical vocabulary, means “death.” It’s used when a patient passes away at a hospital. Since Shouichi was little, he’s had a weak constitution. His father gave up on him early, and decided that his younger brother, Kyouji, would take over the hospital. Even so, it seems like the two of them got along well. But Shouichi got into MMORPGs. And in 2022, he became a prisoner of Sword Art Online. When Shouichi came back, Kyouji was the one person he told about how he’d been feared as a real murderer in that world. To Kyoji, his brother seemed like a hero. Shouichi says that everything about the Death Gun plan, including the murders, was a game. That there was no difference between it and how, in SAO, they’d research their targets, ready their equipment, and carry out attacks.