Shūkurō Tsukishima is an extremely tall young man who always dons a simple outfit consisting of a plain white shirt, black trousers and suspenders. His most remarkable features are his wavy black hair and large, innocent-looking dark eyes. While unassuming at first sight, his looks conceal a dangerous, sinister nature. While not reading every book he can get his hands on Tsukishima finds amusement in toying with people, driving them to insanity with his one of a kind ability. Normally taking the shape of a regular bookmark, Book of the End is a sword that can insert Tsukishima's existence into the past of people and environment he cuts. The fact that its user is a cold, calculating individual who appears to feel no remorse for the intense emotional pain he causes makes Book of the End terrifying to everyone who eventually sees through the curtain of carefully weaved lies. Tsukishima is heavily alluded to having a softer, more dedicated side, however his grim and mysterious nature does not allow for anyone to know for sure if that really is the case.