Some TMNT stuff really isn't for little kids.
In the IDW continuity, Michelangelo, just like his brothers, is a reincarnation of one of the sons of Hamato Yoshi in medieval Japan, who were murdered by Oroku Saki. He began his new life in the present as a water turtle hatchling in the laboratory of StockGen Research, Inc., Baxter Stockman's genetics laboratory where he served as a guinea pig for an experiment to bred naturally armored super-soldiers. Some ninja tried to seize the Turtles and various other research results from the laboratory, including a super soldier mutagen. The intervention of his also reborn father, now the lab rat Splinter, resulted in the turtles and Splinter being doused with a chemical cocktail which triggered their mutation.
In the fifteen months that followed, Michelangelo was extensively retrained by Splinter in ninjutsu, with a pair of nunchaku as his personal weapons. Along with Donatello and Leonardo, he searched the alleys and rooftops of New York for their fourth brother, Raphael, who had been separated from them during the mutation process. Shortly after finding him, Michelangelo was given an orange mask as a sign of his individuality.
Despite initially clashing with the larger turtle, he befriended the mutant snapping turtle Slash, who admired him as a hero and was given candy by him. When journeying to Dimension X with his brothers, Michelangelo developed a crush on Planet Neutrino's Princess Trib, and served as her personal bodyguard and rescuer during the war with General Krang.
Michelangelo also found himself having to hold his family together during the "City Fall" storyline, where he forced a guilt-stricken Raphael to work with him and Donatello as a team.
When Leonardo was recovered and struggling to overcome his Foot Clan brainwashing at the hands of Kitsune, Michelangelo wrote that they would have to take care of his brother because he couldn't do it himself anymore. To reunite his family, he began roasting hot dogs over a campfire, attracting the others with the smell. When Koya and Foot Assassins attacked the O'Neil Farm in Northampton, he defeated the mutant hawk by crashing a motorcycle into her.
During the "Turtles in Time" story, he flew on a pterosaur in the Cretaceous, became a pirate captain of the Shirley's Revenge, and encountered his mother Tang Shen—and his own baby self in feudal Japan.
He participated in the attack on the Technodrome along with his brothers Leonardo and Raphael, where they fought Krang. However, he was devastated upon returning to New York, where Donatello, who had been mortally wounded at Rocksteady's hands, was barely saved by the Fugitoid Zayton Honeycutt while Michelangelo prayed outside. He was somewhat relieved when Donatello's soul was moved to the body of Harold Lilja's android Metalhead, and remained confident that Honeycutt could return Donatello's mind to his body, and that all would be well again.
Michelangelo was initially horrified when Splinter entered his family into the Gauntlet, an ancient ritual that would end the bloody conflict between Clan Hamato and the Foot. He was assigned Bebop as an opponent, and he and Raphael used their agility and ingenuity to pit Bebop and Rocksteady against one another. He participated in the final fight against the Shredder along with his brothers, with his father as the victor.
However, when Splinter accepted leadership of the Foot Clan, Michelangelo rejected the idea of having anything to do with the organization. He fled into the night and spent the following days living on the street, where he sought to fight crime with his skills. Raphael kept in contact with him during this time, assuring him that he knew how hard it was to be homeless, and that Michelangelo would always have a home with them. Though Michelangelo put on a brave front, this estrangement from his family—and especially his father—took a severe toll on him.
It was during this time that he was tracked down by his friend Mondo Gecko, who offered him a place among the Mighty Mutanimals. Despite some initial reluctance, Michelangelo accepted and quickly became friendly with the Mutanimals, but soon became suspicious of their leader Old Hob. He discovered that Hob, Man Ray and Herman were secretly hoarding large amounts of heavy weaponry without the knowledge of the other Mutanimals, who believed the weapons they'd been seizing were being destroyed. The trio had also jailbroken and recruited Hun to manage their weapons and sell off surplus for profit. This caused a rift to form within the group, and inspired doubts about Hob's leadership. Hob informed Michelangelo that he would never forgive or forget what he had done.
Michelangelo and Slash both left the group. Michelangelo decided to move back into the wrecked lair under the old church, and offered Slash a home there if he wished, but the snapping turtle declined the offer and set out to be his own master for a time. Saddened, Michelangelo cleaned up the lair and made it livable for himself once again, only to be surprised by the arrival of his brothers with a pizza. They offered him a trip with them to Burnow Island, devoid of Foot Clan business, and he happily accepted.
However, the trip proved to be a difficult one as they encountered the hostile mutant Leatherhead, who nearly suffocated and crushed Michelangelo as a way of making Donatello teleport him to New York. And upon returning to the Foot Clan headquarters, Mikey was horrified to see Kitsune threatening his father's life. He attacked the witch to save Splinter, only to have his mind ensnared by her.
Michelangelo attempted to reconcile with his family during the Chasing Phantoms arc, but was put off by the increasingly cold and impersonal tone of the meetings Splinter presided over, leaving for the church lair once again. Raphael initially told him that it was time for him to reunite with the rest of his family. But upon Splinter's sudden and chilling execution of an unarmed Darius Dun, his brothers changed their mind and decided to leave the Foot for good, joining Michelangelo at the old lair.
Michelangelo returned to Dimension X with his brothers in "The Trial of Krang" story arc, in which he met Princess Trib once again before setting out on a complicated quest to find and bring back key witnesses. During the trial, he participated in the defense of the Planet Neutrino from the Malignoid Swarm. Shortly afterwards, he and his brothers were pursued by the demonic Collectors, and Michelangelo was forced on an transdimensional journey with Peter Venkman, which took him to the world of Zoo Amsterdam where the two encountered the Ghostbusturtles.
Upon returning to Earth, Michelangelo and his brothers were forced to deal with the conflict between the Triceratons and their own father. After Splinter defeated his three brothers, Michelangelo attempted to reason with him, but was unsuccessful, instead being transported away with Commander Zom. When the Rat King subsequently threatened the people of New York, Michelangelo accompanied his brothers on a search for members of the Pantheon who could help them, and gained the respect and liking of Manmoth for his clever use of a snare.
He also came into conflict with his father over a number of orphaned children that the Foot Clan was caring for. When Splinter agreed to care for them as long as they were trained to be Foot ninja, Michelangelo was the only one of the Turtles to fully reject the idea. He attempted to take the children away from the Foot so that he could raise and train them himself; when Splinter and his brothers caught up to him, he fought his angry father until Splinter capitulated. Leonardo then thanked him for standing up to Splinter.
He accompanied his brothers to Burnow Island to thwart Agent Bishop's invasion, and was briefly reunited with Slash when his friend was freed from Bishop's mind control. When it was revealed that Bishop had implanted a nuclear bomb in Slash's body, Michelangelo gave him a candy bar and a hug, and tearfully called him a hero.
In this series, Michelangelo appears less childish than in previous incarnations; and is quite a glutton with a special fondness for pizza. Through this passion and his cheerful nature he makes best friends with the pizza delivery boy Woody Dirkins, despite a brief rift after Slash attacked Woody and frightened him off. Woody is one of several friends that Michelangelo makes over the course of the series, such as Slash, Trib, Mondo Gecko, Peter Venkman, Manmoth, and various other characters.
His positive, compassionate, open-hearted personality causes Splinter to characterize him as a "bright light that shone unceasingly through so much darkness." He tends to think positively even of people such as Old Hob, whom he once speculated might become a good guy. He is highly idealistic, and due to his love of comic books, he sometimes dreams of being a crime-fighting hero.
He also serves as a peacemaker within the structure of his family. He often intervenes when a fight breaks out among his brothers, reminding them of what is important, and has successfully grounded Raphael when the latter was raging out of guilt. His ideas for bringing his family together can be very simple (such as roasting hot dogs) but typically work well.
He also demonstrated over the course of the series the ability to speak and read Japanese fluently—an ability that is not shared by his brothers—and thus is capable of translating the Ashi no Himitsu without any trouble.
- It is revealed in Issue #30, that Mikey is left-handed. This is shown when he writes a letter to Woody.
- After the events of Issue #50, Michelangelo begins using a grappling hook as a weapon, and he retains this item even after he is given a new pair of nunchaku. This reflects Michelangelo's change of weapon in the 1987 TV series, when his nunchaku were written out due to censorship.
- It has been mentioned a few times in the comic book series, that Mikey both reads and collects comic books, and it is shown in issue #67 that his collection consists of Batman, Spider-Man, and The Incredible Hulk comic books. The view of his bedroom in Issue #65 reveals that he also collects the manga Akira.
- In issue #22, Mikey can be seen with a copy of the comic book, "After the Fire 100 Page Spectacular 2012".
- In issue #39, it is shown that Mikey cooks breakfast for the rest of the Turtles and Splinter; however, he is not a very good cook, as when he tried to make scrambled eggs and toast, he wound up burning the toast and dropping the eggs.
- In The Secret History of the Foot Clan, part 4, it is revealed that Mikey can read and speak Japanese fluently.
- It is mentioned and shown throughout the comic book series that Mikey likes to play video games, and is capable of easily beating his brothers at them.
- In "Kingdom of Rats", part 3, Mikey says "Action" is practically his middle name, declaring his full name to be Michelangelo Tezuka Action Hamato, to which Donatello reacts, "Tezuka?". Mikey's random inclusion of this name could be him remembering it was his own in his previous life or one of his brothers, and just using it as his middle name. This is also the first time in the IDW continuity that one of the turtles claims Hamato as not just his clan, but his surname, too. Manmoth becomes especially fond of Mikey, always respectfully addressing him as Michelangelo Tezuka Action Hamato. Later in the same issue, Mikey tells Manmoth that "Genius" is practically his third middle name.
- He may have also adopted Tezuka as part of his name because of his interest in manga, since the "father of manga" was Osamu Tezuka.
- Mikey knows how to juggle.
- Mikey can wield and spin nunchaku with his feet as well as his hands.
- As seen in the Michelangelo Macro-Series issue, Mikey is the second of his brothers to be shown to have regained memories of his life as a human, specifically of early training with his nunchaku under his father.