Mello (Mihael/Michael Keehl) is the older of L's two potential successors raised in Wammy's House, Watari's orphanage for gifted children, in Winchester, England, United Kingdom. When it is decided that Mello should work with the other successor, Near, Mello refuses, citing an inability to work with Near, to whom he is considered second in ability. Near is more intelligent than Mello, but Mello has more ambition than Near. This results in Near thinking things out better than Mello, but sometimes being so uninterested in his surroundings that he verges on inactivity. Meanwhile, Mello has a brazen and driven personality, driving him (unlike Near) to be the first to resume actively hunting Kira; however, Mello lets his emotions cloud his judgment, often leading to rash decisions that impede his progress.
While Mello is certainly a genius and more intelligent than most people, the concept of being only the second most intelligent person at Wammy's House, behind Near, fuels the inferiority complex that defines Mello's character. Mello verges on being amoral in his obsession with being the one to take down Kira and is willing to do "whatever it takes", tactics which include kidnapping and being an accessory to murder. In the manga, after Mello has successfully stolen a Death Note, he even goes so far as to attempt to blackmail the President of the United States via telephone into giving him funds and resources to aid his hunt for Kira, threatening that if his demands are not met he will use the Death Note to force the president to launch the United States' nuclear missiles and start World War III. Arguably, Mello is not even trying to defeat Kira out of a sense of "justice," but because capturing Kira will not only get revenge for L's death but also prove to the world that Mello is indeed the worthy successor to L's status as the world's greatest detective, and not simply runner-up to Near. As Mello describes his goal in his own words, "I will be the new Number One!" Similar to L's fondness for sweets, Mello is near-constantly seen eating bars of chocolate, usually by ripping off an entire chunk in his mouth with a dramatic flourish. Also, just like L, Mello thinks and reacts quickly, and uses less conventional methods to solve his cases.
After Mello leaves the orphanage, there is a four-year time jump.
13: How to Read states that Mello has "an excellent mind" and that he "sometimes lets his emotions get in his way". The book cites Mello's "hatred of Near", which created "a flaw in [Mello's] personality". Obata points out that Mello's envy and hatred of Near was only one-way, and that Near honestly "liked Mello" The book states that Mello isn't purely evil, citing his apology and genuine care for Matt's well-being.Tsugumi Ohba, the writer of Death Note, stated that Mello "works hard for everything". Ohba added that Mello's name "doesn't really stand for anything."
Mello is voiced by Nozomu Sasaki in the Japanese anime, and David Hurwitz in the English version