Shinkawa was one of the top members in the red guild «Laughing Coffin». He was a master of the «Estoc Thorn Sword» that was bathed in the color of red. He holds a grudge against Kirito and the clearers that defeated Laughing Coffin in the anti-PK raid. He was also partners with Johnny Black, and together served as a combination where they poisoned and killed.
After his release from SAO, through the recommendation of his brother Kyouji, he began to play Gun Gale Online. The two looked to another Laughing Coffin member and began to plot a ingenious plan to kill players in both the virtual world and the real world. He enters the Bullet of Bullets tournament under the name Sterben (ステルベン Sutenruben?) to prove his "true" killing ability to the rest of the world. He would stun people with special shells from his L115A3 Silent Assasin sniper rifle and then get up close to shoot them with his «Death Gun», a 7.62 X 25 handgun. While he commited 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 watched the other players type their real addresses during the BoB registration process. His plans were foiled by Kirito and Sinon, and eventually goes to prison after the incident had passed.