Yuno Grinberryall/Biography

Yuno, along with Asta, was left in front of a church in a village called Hage when he was an infant. He grew up at the church and spent most of his day with Asta. One day during a trip home after grocery shopping with his foster family, Yuno overheard a few villagers talking about living in the Noble region of the Kingdom. After the sister explains the social status within the Kingdom, Yuno hears Asta's dream to become the Magic Emperor for the first time.

Sometime later, a thug tried to take his necklace away from him so that he could sell it for the money. However, Asta stepped in and tried to take it back. At the end, the thug decided to leave without the necklace after Asta kept charging at him. Since then, Yuno stopped crying and decided to take Asta's dream to be the Magic Emperor as his own as well. One day, during their time growing up at Hage, Yuno and Asta goes into the forest and stand on top of a hill while facing towards the Noble region. Asta begins talking about their relationship as a family despite the lack of blood relation in which Yuno is in a complete agreement about it. In that moment, they promise to treat their future comrades the same way they treat each other; as a family.

Yuno and Asta also trains from time to time to sharpen their combat abilities. The training usually consists of Yuno blowing Asta away with his magic while the latter tries to charge at him. After seeing Asta fails multiple times, Yuno suggest that they stop in which Asta refuses. To Yuno's surprise, Asta manages to breakthrough at one time in which he reveals that his persistence helps him to success.

Years later, Yuno still lives at the church, where he takes care of chores such as doing laundry, chopping firewood, or taking care of the younger children. When he turns 15 years old, Yuno receives his grimoire during the Grimoire Acceptance Ceremony. Realizing that he has received a grimoire similar to the one possessed by the first Magic Emperor, Yuno declares his ambition to the public while brushing off Asta's declaration of rivalry. Later that day, Yuno was confronted by Lebuty, who manages to snatch his grimoire and immobilize Yuno with his magic. Once again, Asta steps in to save him, after which Yuno clarifies his previous statement during the ceremony and declares that Asta is truly his rival.

Six months later, Yuno attends the Magic Knights Entrance Exam, where he manages to easily perform all the required tasks. During the combat test, Yuno fights against Salim from a noble House Hapshass, which he finishes the moment it started. Yuno has managed to impress the captains so much that all nine of them show their desires to put him in their ranks. Yuno decides to join the Golden Dawn, believing that entering the strongest squad is the fastest path on becoming the Magic Emperor.

Before he leaves for his squad, Yuno stops Sekke Bronzazza, Asta's opponent at the exam, from harming Asta whom is at the toilet. He intimidates Sekke by saying that he is not worthy of Asta before Yuno leaves without meeting Asta.

A few days later, Yuno is dispatched with two of his squadmates to explore the newly emerged dungeon. As they enter, Yuno immediately activates one of his spells when he sees that Asta is struggling with one of the dungeon's traps. After he saves him, Yuno confirms that he has paid his debt when Asta saved his life. Yuno and his group then meet with Asta and Noelle Silva where Yuno is standing there quietly as his senior, Klaus Lunette, begins a conversation with Asta in which he thinks to be a waste of time.

Not long after, Klaus ends the conversation and orders Yuno to take them to the center of the dungeon after Mimosa Vermilion located it with her spell. Along the way, Yuno warns Klaus to not underestimate Asta after hearing him giving condescending remark about the said person.

Not long after, they finally arrive at the gate to the center of the dungeon. Unfortunately, after an ambush manage to breakthrough Mimosa's defenses, Yuno and Klaus prepare to fight as they encounter the perpetrator. Klaus immediately asks Yuno to be his support in the fight as soon as the mage from the Diamond Kingdom, Mars, tries to attack Mimosa whom still recovering. They ended up in a stalemate where each sides unable to breakthrough the other's magic attacks.

Suddenly, Klaus asks Yuno to leave and conquer the dungeon on his own. Yuno declines at first but soon agrees after Klaus is giving him a direct order. However, Yuno quickly turns back to protect Klaus from an incoming attack and declaring that he will not leave his comrade behind.

After he explains himself to Klaus, Yuno releases his magical power and activates two spells at the same time. He then declares that the Golden Dawn will be the one conquering the dungeon. Unfortunately, as the fight continues, Mars manages to suppress Yuno with the latter barely able to remain standing as his spells begin to vanish. Mars continues his assaults at Yuno with the latter is struggling to evade every attacks. Yuno tries to launch another attack but it results in another failure as Mars reinforces himself with crystal-made armor.

Mars then asks Yuno to give up and admit defeat in which reminds him of the past when he is training with Asta. The memories lead to Yuno's refusal on admitting defeat as he continues to evade Mars' merciless attacks. When one of the attack about to hit, Asta manages to step in and stops it. Asta's action slightly irritates Yuno as the former saves him yet again. He then begins arguing with Asta about his circumstances with the former tries to cover for his struggles. The arguments stop when Asta decides to join Yuno in the fight. Soon after, the fight continues with Mars is creating a number of clone puppets with his magic to attack all of them. Yuno is then stuck fighting these puppets while Asta is able to defeat Mars.

After Klaus restrains the unconscious Mars, both the Golden Dawn and the Black Bull members enter the center of the dungeon with Asta forcefully cuts down the door. They are quickly taken by surprise with the spectacles they see behind the door. As soon as they enter, each members quickly explores the treasury and trying different magic tools they find within it. Yuno then notices a scroll surrounded by wind streams. When he opens it, he finds writings that he could not understand. Before he realizes it, the scroll and his grimoire begin to shine and the writings mysteriously disappear.

Yuno then hears Luck Voltia warns them to get away from the door, but Yuno does not manage to react fast enough and is ambushed by Mars' attack. The mage of the Diamond Kingdom manages to trap him within a crystal structure in which renders him immobile. The crystal structure also prevents him from using his grimoire as Yuno is unable to help Mimosa and Noelle from Mars' attacks. Yuno then tries to slowly breaks his binding with his magic as he witnesses Asta whom is releasing a water-based attack.

Unfortunately, Mars is able to suppress Asta and about to move in for the kill. Seeing this, Yuno forcefully breaks the crystals that are binding him and quickly searches his grimoire for a spell to stop Mars. He is unable to find a suitable spell but he refuses to give up. At that moment, Yuno's surroundings suddenly stop moving as he find a little girl with a pair of wings right by his side. The said girl then easily defeats Mars with a single blow. After that, when Yuno looks back at her, she has already disappears and similar writings with the one he found within the scroll earlier are appearing on a page of his grimoire. Not long after, the dungeon begins to collapse.

Seeing that the dungeon is collapsing, Yuno quickly creates a vessel for all of them to escape. They quickly head to the exit after failing to fulfil Asta's request of taking Mars with them. They manage to escape from the dungeon mostly unscathed due to Luck's guidance and effort of getting rid of any falling debris with Klaus. As soon as they are outside, Yuno quickly instructs them to take Asta to a safer place for Mimosa to properly heal him. After Asta regains his consciousness, Yuno is suddenly being hugged by Klaus along with Asta as the nobleman acknowledges his worth.

A week after completing the mission, Yuno along with Klaus and Mimosa travel to the Magic Knights headquarters to report about the mission accomplishment where they encounter Asta and Noelle. The five of them then head to the designated venue together. Upon arrival, they are greeted by the Magic Emperor himself, Julius Nova Chrono, whom then examines the magics they took from the dungeon. While in the presence of the Magic Emperor, Yuno and Asta ask Julius about the method they should use to attain the Magic Emperor title in which Julius simply says that producing results are very vital for the acknowledgment.

Afterwards, Yuno is invited to attend a War Merits Conferment Ceremony that honors several Magic Knights that have produced the most results. At the end of the ceremony, Yuno and dungeon exploring squadmates are scrutinized during the celebratory banquet in which Yuno decides to remain silence. While watching Asta confronts the honorary Knights, Yuno becomes curious when one of those Knights, Leopold Vermilion, is declaring Asta as his rival. Mimosa then explains to him that the two brothers from the Crimson Lion squad are her cousins.

Not long after, someone suddenly enters the banquet hall and reveals that the Royal Capital is under attack. Yuno then joins his colleagues as they figure out a counterattack strategy. At the end, Yuno leaves along with Alecdra Sandler and Mimosa to the Northwest District of the Royal Capital. As they arrive, an army of corpses quickly surround them from every direction. Yuno then proceeds on defeating every corpses that he sees while Mimosa is healing the injured.

After all of the corpses are defeated, Yuno's grimoire begins to shine and black substances manifest under their feet. The said substances manage to transport both Alecdra and Mimosa away from the Royal Capital as a mage suddenly makes an appearance. When she begins to attack the citizens, Yuno whom is able to escape the spatial magic spell, quickly engage in a fight against her.