He goes by the nickname Meruka Kuramitsu. Dissatisfied with the prospect of a regular and unexpressive life that he can predict with 100% accuracy, he works as a for hire bomber and is famous for his ability of escaping from his captors. He is fourteen years old when he chooses a nickname based on a comic character liked as his alias.
He refers to both his adult self and his young self as a robot that simply idles by life following common instructions. However his pessimistic behavior is usually counter balanced by Mana's curious and cheerful disposition, and she usually requires so much attention that Mitsuru doesn't really have the time to feel down.
Kara no Kyoukai
n 1998, during the Möbius Ring chapter, Kamekura takes an interest in Shiki Ryougi when she saw his face and recognized him as the bomber right after he fulfilled a job. At that point he noted that he must take her out to protect himself, and began to pursue and set traps for Shiki. However, she easily escaped from all his traps and he is trapped by Shiki, who overpowers his ability with her Mystic Eyes of Death Perception and permanently damages his right eye, sealing off his precognition abilities for good.
Because Shiki correctly noted that Mitsuru needed to "pave the path" of the present using what he saw with his left eye in order to achieve the logical result that would be shown in his right eye, and thus what he sees is not the future per se, she is able to defeat him. As the "prediction" could actually be be killed, it would destroy the "certain factor" of his calculations. When Shiki destroys his right eye, Kamekura is unable to make accurate predictions and encounters unknown unforeseen events; the detonation of the bomb he set up is delayed by five minutes, and he is defeated.
In Möbius Link, he is close to 25 years old and works for Mikiya Kokutou's agency while keeping his main job of being an author of children's stories. His work for Mikiya usually involves doing background checks and sometimes he will be requested to partake act on proper investigations. Occasionally, Mana Ryougi usually kills time reading books or speaking with him in his office; Kamekura will grudgingly acknowledge that Mana is his savior, as she recommended him to the agency when he was in extremely bad economical shape, forgiving his many debts to the syndicate.
He possesses a Right Eye that can see the future, while his Left Eye can see "the path" to achieve that future.
Mitsuru possesses Precognition in his right eye and the ability to achieve the future in his left eye. Able to foresee the future like watching a film, he right eye is able to see something like the ideal score on a test five minutes later, a day later, or even a month later. The left eye views the present and projects the methods by which the viewed result can be actualized like the method of achieving that ideal score. Like having a test’s answer sheet filled in before him, all the necessary measures for fulfilling the future are instantly projected in his left eye upon viewing it. If he acts according to the image, the film playing in his right eye becomes the unchangeable future. He doesn't view it as the future, but rather the "obvious result" created from the accumulation of the present, causing a variety of emotional issues for him.
While reality cannot be determined by formulas because it is a fluctuating value unable to be determined until the answer is obtained, he is able to fix the value beforehand to make the answer unshakable. Weighing together the variables called reality, he actualizes the "successful future" at the cost of his own free will. Ignoring "wishful observations" like his own interests and emotions, he views himself as a slave for the purpose of bringing about the determined future. When given a job like destroying a floor of a hotel with no casualties, he wishes for the result, sees the hotel wrapped around by black smoke, and simply acts on the vision. He can even see variables like the resulting casualties and property damage. While the method by which the future is achieved may slightly differ, such as someone taking a different path or people arriving slightly later, the overall scenario will play out according to his wishes. The only time it completely fails is upon meeting Shiki and having not seen her name with his right eye that day. It is the first time his right eye has failed in such a way, bringing about his obsession of wondering if he is able to kill her.
One main difference from predicting the future is that he must be actively watching the location of the future in order to bring it to absolute completion. He cannot be an indirect third party if he is to weigh all the variables together. Even if he can measure the factors of reality and understand the result, he has to see "that instant" himself because it is the future seen with his own view. His first three attempts at Shiki's life fail because he only sees "a future where he placed explosives in a place he lured Ryougi Shiki to", when the absolute condition of having her dead would require him to see a vision of her dead body. This puts him at a disadvantage when the target knows about him because it is known he is located in their line of sight. He can see multiple possible outcomes when not fully present at the site, allowing him to plan contingency futures based on the different outcomes.
The ability, calculation of the future, differs from and exceeds prediction of the future. The future is normally uncertain and unable to be reached out to because it is not there, and prediction only allows for seeing a possibility of a future that may eventually occur. Calculation is an abnormal ability able to determine an outcome through his own will which will definitely occur.