Mikan's death poster in the trial room is crossed out with a nurse's cross, in reference to her Ultimate talent. After Nagito caught the Despair Disease, Mikan took care of him along with the others. However, she also caught the disease, and despite his terrible condition, he noticed that she had fallen into despair. Because of this, and the murders she committed for the sake of despair, Nagito lost all respect for her and considered her an enemy, worthy of the name "Ultimate Despair". Unlike the others, he wasn't fooled by her act during the trial and he bitterly refused to forgive her. Hajime begrudgingly singles Mikan out as the murderer, to which many disagreed at first. Oddly, Nagito agrees and states that the culprit this time was someone he could not forgive, and the reason is later revealed to be because unlike the others, the culprit did not kill for a hope of escape, but for despair. While her title in the official English translation is Ultimate Nurse, Mikan's original title is Super High School Level Health Committee Member. The "health committee" or “health and hygiene committee” (since 保健 hoken means both “health preservation” and “hygiene”), is a common student committee in Japanese high schools with the duty of preparing and administering first aid during school events, monitoring the school's state of sanitation and promoting health-preserving behavior. haha@?@@”haha!”:hahahahahaforgivemeloveme forgivemeloveforgivemeeeeeeeeeeeeeeeeeeee" ( Mikan's cottage post-fifth trial)

The two-in-row murder cases of Natsumi Kuzuryu and Sato affected Mikan's class, still showing no spirit when Chisa announced the annual practical exam that will start on the next day. Not only that, she and her classmates must bid their farewell to their beloved teacher Chisa as she transferred to the Reserve Course after the bombing incident involving one of her classmates, Nagito. Kyoko Kirigiri • Yui Samidare • Detective Library members • Fuhito Kirigiri • Gekka Ryuzōji • Hajiki Yaki • Jin Kirigiri • Licorne • Mikado Shinsen • Nazuna Tooakitsu • Norman's Hotel Murder Case participants • Sachi Mizuiyama • Sae Yozuru • Salvador Fukuro Yadorigi • Suisei Nanamura • Tadashi Asakura • Tōkichirō Endō • Tsukiyo Nada Um...you know... Um...um um um um... Uhhhh...my mind is drawing a blank...from nervousness... And...I went through all the trouble preparing 5,000 different topics to discuss after introductions!" Junko made Mikan watch a brainwashing video containing the recording of the first Mutual Killing game using Ryota's abilities to influence people's minds, thus turning her into an Ultimate Despair. At the beginning of the episode, Mikan is seen massaging Junko's legs. Mikan said to Junko that her classmates are wonderful, especially her homeroom teacher, Chisa, and her class's representative, Chiaki Nanami.After Nagito awoke from the simulation, he learned that all of his friends, including Mikan, were alive and awake from the Neo World Program. He boarded the boat with the rest of Class 77-B and they all then headed for the Future Foundation Headquarters. I'm drowning in so much love... From the bottom of my heart, I just don't care about anyone or anything." Mikan appears in Sengoku Asuka ZERO x Danganronpa 3: The End of Hope's Peak High School collaboration as one of the many collectibles. At some point after the end of the Killing School Trip, Mikan and the rest of her comatose classmates were awakened by Hajime, whose personality had blended with Izuru Kamukura's due to his experiences in the Neo World Program. Purged of Junko's brainwashing, the now-former Remnants of Despair joined Hajime on a ship that took them to the ruins of the Future Foundation headquarters, where Ryota Mitarai was attempting to broadcast a "Hope Video" to brainwash the world into never feeling despair again. Her first name (蜜柑) means “mandarin”, as in the type of orange, while her last name (罪木) means "sin tree".

Chiaki is the first person who let Mikan play video games and have fun with her by staying calm. In one of the episodes in Danganronpa 3 - Despair Arc, a then brainwashed Mikan apologizes while Chiaki acts puzzled and pushes Chiaki to a secret passageway. In the end, Mikan regrets the whole thing and joins her classmates to stop Ryota to not upload a brainwashing video of hope. Ryoko Otonashi • Yasuke Matsuda • Chihiro Fujisaki • Isshiki Madarai • Izuru Kamukura • Jin Kirigiri • Junko Enoshima • Kyoko Kirigiri • Makoto Naegi • Mukuro Ikusaba • The Steering Committee • Sōshun Murasame • The Student Council • Yuto KamishiroJust leave it to me! I'm really good at digging holes! I used to help bury things, and I used to get buried a lot myself, so it's gonna be okay! Which one do you want me to do? I'll help you with either!" After bidding her class a final farewell, Chisa activates a bomb that fakes the death of Class 77-B. Mikan and her class stand outside the school grounds as they watch Hope's Peak Academy's destruction. However, deep down, Hiyoko actually does care for Mikan. For example, in Danganronpa 3 manga, it was revealed that Hiyoko accidentally hurt Mikan when she and Mahiru ran into her while walking to school. Losing focus as she was too busy bullying Mikan, Hiyoko tripped over her sandals and scraped her knee, accidentally tripping and wounding Mikan, who was trying to clean Hiyoko's wounds, as well. After seeing what she had done, Hiyoko ran away in shame, forcing Mahiru to go after her. When Mikan tended to Hiyoko's wounds in the nurse's office, Hiyoko tearfully claimed responsibility for the incident and offered to clean Mikan's wounds in return, an act which delighted the Ultimate Nurse. The two were later seen walking out of the office holding hands, showing that Hiyoko did think of Mikan as a friend. It was also shown that Mahiru cared for Mikan during their times at Hope's Peak Academy when Mahiru took a photo of Ibuki, Mikan, and Hiyoko to cheer sad Mikan up after Hiyoko yelled at her for being late. Mahiru defended Mikan and tells Hiyoko to stop scaring Mikan after they discover Natsumi's corpse. After the events of the Tragedy and Killing School Trip had ended, Mahiru is seen celebrating with Mikan, along with Hiyoko and Ibuki. Mahiru even approaches Mikan later on, and the two are seen talking together. Nagito...is never going to die! I will save him by any means necessary! Nagito's life...is my responsibility. I will save him by any means necessary!"

Mikan makes a cameo appearance in Danganronpa Another Episode: Ultra Despair Girls on a poster in the hospital in Chapter 1. Hehe...I'm so, so, soooo happy...I was able to play with a friend... Hehehehehehehe... Thank you very much, Chiaki."She previously attended Lapis Lazuli Girl's High School before enrolling in Hope's Peak Academy as the Ultimate Nurse, in Class 77-B. Her life at least seemed to get better, and she befriended her first friends ー Ibuki, Hiyoko, Mahiru Koizumi, and Sato. During their time together, they discovered a corpse in the music room. This was later revealed to be Fuyuhiko Kuzuryu's sister, Natsumi Kuzuryu, who was murdered by Sato. A few days later, Sato was killed by Fuyuhiko. Hiyoko suggested that Mikan enter the classroom, where Mikan found Sato's corpse. This part of Mikan's life was revealed in " Twilight Syndrome Murder Case". Danganronpa 2: Goodbye Despair [ ] Prologue - Welcome to Dangan Island! Panic at the Heart-Throbbing School Trip!? [ ] While under the influence of the despair disease in Chapter 3, Mikan recovered her memories of school life. At the end of the trial that unveiled her identity as the culprit, she revealed that she did it for the sake of 'her beloved', claiming that they forgave and accepted her for who she was, in stark contrast to the maltreatment she had been exposed to her entire life, and that they would appreciate her actions if they were alive.