He may come off as cynical and often utilizes questionable methods. He mostly takes up solving cases out of a sense of boredom rather than duty. However, he does have a strict moral code and is unwilling to cross morally repugnant standards. L has spent most of his life dedicating himself to solving crime cases, and hunting down and apprehending notorious criminals and felons around the world. He is implied to suffer from loneliness, internal torment and a low esteem, even calling himself "a monster", at one point. He also possesses an unusually high intellect and uncanny skills in strategisation, deduction, observation, reasoning and profiling, which have given him a high reputation amongst law enforcement agencies around the globe. At the start of the series, L carries out his own investigation of a series of mysterious serial-killings across the globe, all of which are carried out by an apparent supernatural serial-killer known as "Kira", which is the Japanese trans-literation of the English word "killer". After deducing that the serial-killings are all connected and perpetrated by a single mastermind and are sourced from Japan, L allies himself with the Japanese police force and assists them in investigating the murders. Although he strongly suspects the series' protagonist, Light Yagami, a high school genius and the son of detective superintendent Soichiro Yagami, one of the primary members of the Kira investigation allied with L, to be Kira's alter-ego, he is unable to prove his theory, due to lack of evidence, but nonetheless remains suspicious of Light and carefully observes him. The majority of the series' initial focus is on L and Light's complex, cerebral and intricate psychological mind-game of cat and mouse, as both utilise their wits and intellect, in an attempt to outdo the other and expose them. Though L comes very close to exposing Light as Kira, he is eventually killed by Light himself before he can do so, but before his death, he finally acknowledges his suspicion that Light is Kira came to be true. Although L's death regressed the Kira investigation's progress, he had prepared himself with a contingency plan to ensure that someone would continue L's work in hunting down and apprehending Kira, by selecting two gifted child orphans to be his potential successors, one of whom eventually succeeds in exposing Light as Kira. Although his true identity and birth name is obscured in mystery throughout the series, L utilises a number of aliases to maintain his anonymity, such as "Hideki Ryuga" or "Ryuzaki", the latter of which he uses as his primary pseudonym throughout the Kira investigation.