Arisu came from a prestigious family. His father is a superintendent in the education department.
Arisu lost his mother as a child. He asked his father during the cremation why they couldn't see her anymore to which his father responded by reprimanding him, saying that he did not like stupid people and that if he wanted his affection, he had to become the child he wanted him to be.
When Arisu was in 5th grade, he was in the same class that Karube was in. After being beaten up by another child, Karube arrived to help him, but the children ran away when he saw him. When Karube asked if he was all right, he answered that he saw a massive mole on the children's neck and a weird hair growing out of it while he was beating him up. The next day they went around spreading the word and even followed the children on the way home until he finally broke down and surrendered. His father would often meddle with Arisu's life and compare him to his competent younger brother to the point when his father sometimes complimented him, Arisu felt like he didn't even exist.
When Arisu arrived at High School, he was enrolled in the same class as Chota. His first impression was that he was idiotic and hopeless and didn't want to become friends with him. When Arisu began practicing guitar due to his well-intended teacher's influence, his father moved him away from Arisu's school to cease Arisu's newfound hobby. Full of anger, Arisu threw a rock on one of the glasses of his house. He immediately regretted it because he'll be compared to his brother, but Chota arrived and said that he could tell his father he threw it and ran away. The next day he gave a piece of bread to Chota to thank him and asked why he did this. Chota answered that he looked sorrowful, and he'll do it again if he'll give him some bread. Arisu realized that he was idiotic and hopeless, but he was also the world's kindest person. From this day, they became close friends. Arisu's younger brother at most of the time, belittled him and showed little respect to his older brother. He placed 10th in a national mock exam and showed off and beat his older brother in academics and sports.
One day he and Chota were robbed of their money and beaten up by gangsters. Karube arrived and asked if he remembers him. Then he beat up the gangsters. After that, he became close friends with the two. Even though they are minors (age of adulthood in Japan is 20), they often hang out at his bar and drink. When the story starts, Arisu has inevitably failed a mock exam. He talked was talking to Chōta, and pointed out that there was a statistical chance of him passing even though he bubbled “C” for every answer. Later he went to Karube's bar to avoid being compared again to his brother by his father. When Karube warned him that wasn't the right solution, Arisu wished that to win at the lottery or that a disaster happened to the city so he could be more responsible. Chota proposed them to go to Shibuya to party. When Arisu told him that they aren't any train at this hour, he simply said that they'd walk. After a long walk, they decided to wait for the first train to go home because they were too tired. While they were waiting, they saw fireworks, which surprised them because it's 4 AM. When suddenly, a big one exploded and dazzled them.
Arrival at Borderlands
The three woke up in Karube's bar, all covered with dust. They went outside and saw that their nobody anymore. While Karube was worried about what happened, Arisu and Chota were excited because they felt free and thought that's a dream and start to have fun. After a long time, Arisu and Chota asked how a dream could last so long. Karube told them that it's time to take this situation seriously and that this world is real. Suddenly they hear some music and discovered a temple full of food. Arisu and Chota ran in and started to eat while Karube warned them that something is wrong. A woman came out of the toilet in the temple. When Chota asked if she wants to play with them, she asked if it's their first time and if they penetrate the temple without knowing anything. When Karube proposed them to get out of here, she warned them that now they're in, they can't go out and they must stop thinking it's a dream or they'll die. They discovered that lasers blocked all the entrance. A screen appears written on it: "Game" and an image of a card:" Three of Clubs "
Three of Clubs
The girl presented herself as Saori Shibuki. After explaining the rules, Arisu asked what the meaning was for all of this, but Saori answered that now was not the time to ask questions. Karube draws a paper fortune first and obtains a "Best luck". Then Chota draws one and obtains "Little luck" with an equation to resolve. Arisu tried to help him. Chota answered wrong and nearly escaped from the fire arrows thrown at him. It's Chibuki who draw the next paper fortune and obtained "Misfortune". While she and Karube were trying to find the answer, Arisu realized that he was selfish to desire to leave his old life and want to go back. Karube and Shibuki answered the questions but got it wrong. When the arrow started to be shooting, Arisu's legs refused to move. Karube kicked in his legs and yelled that he could do it because he's his friends. Arisu's legs finally moved, and he was able to put himself in a shelter. But Chota didn't make it in time and received an arrow in the leg. Karube arrived and protected him with a table. Impressed and determined, Arisu went to draw the last paper fortune wishing to be "Great Luck" but fall in despair when he saw that it was "Terrible Luck". But to Arisu surprised, Karube decided to answer and entrusted his life to his judgment.
While he was thinking about the answer, he asked himself why he used a paper fortune for the answer. Then he suddenly understood the purpose of this game and answered the question. But to the surprised of the others, he answered wrong.
He explained to the others that there was no way they could've solved this problem and that he understood that the paper fortune's utility is to indicate where is to arrows will be thrown or where is the safe point with Karube's fortune (south).
The four ran in this direction. They found a hidden shelter and get into it in time. A message announced to them that they've won the game. After a short celebration and they discovered that a sort of register print of each them a 3 of clubs card and a paper called "visa". The four went to the hospital to heal Chota's wound. Shibuki explained what she knows about this country: The Borderlands.
She explained that many people like us are there: the players. Every game starts at nightfall and may take place everywhere. But before she could say more, they arrived at the hospital. While Saori was healing Chota's wound and Karube searching for food, Arisu waited on the top of the roof when he met another player. The player told him that all his friends are dead, and even if he survives, there will always be another game. Because he is fed up with these games, today is his last day because he quit the game. Arisu asked him what does he mean by there will always be another game. The player replied that the visa ends today witch means it's the end before being hit by a laser on the head coming from the sky. Arisu understood that because of the game with a difficulty level of 3, there was a visa expires in 3 days. So they must continue to participate in these games if they want to live.
Second Day of Sojourn
The next day, the four went fishing and had a lot of fun. During this moment, Arisu realized that even if he is in an awful place for the first time in his life, he is glad to be alive and doesn't feel alone. After diner, Karube proposed that tonight they participate in another game. It is finally decided that Chota won't participate to a game to heal his wound, and Shibuki will stay with him. Arisu and Karube went into the area of a game the "Five of Spades".
Five of Spades
They sympathized with another player Nitobe who explained to them what means the value of the card and the suit. After the explanation of the rules, the three stayed group and waited to see "it". After a moment, they heard a strange noise upstairs. They went to see what was going on, and they saw "it": the Horse Head with a machine gun. The three ran away as fast as they can. While they were going on the floor below, Arisu understood that they wouldn't make it if they keep running downstairs, so he and Karube stayed on the floor below while Nitobe kept going downstairs. Like Arisu thought: "it" went downstairs and killed Nitobe before he could be reached and Karube started to look for the safe zone, but they founded "it" and were separated. Karube ran away, and Arisu hid while "it" passed next to him. After that, he rested a bit and started to think of what "it" would do to win this game. He understood that "it" was prepared that players could try to chase him and would carry multiple guns. After that, he realized that "it" tried to make sure that no players stayed on the 4th floor by shooting on them even if they are to fare away to be hit, which means that the safe zone is on the fourth hallway.
Only one minute remained when he arrived in the fourth hallway. "It” was waiting there, but Karube knocked him down from behind. Arisu took advantage of it and started to look for the safe zone and finally found it, but when he entered in, he discovered that two buttons must be touched at the same time to clear the game. He yelled for help, and Usagi came in the safe room. They both pressed the buttons in time and cleared the game with make "it" head exploded. Arisu proposed to Usagi to come with them, but Usagi and warns him that some game would require betrayal between players. Finally, he and Karube, who has been injured, left and founded Shibuki and Chota.
Seven of Hearts
Fourth day of sojourn, Karube, Arisu, Shibuki and Chota decides to play the next game as Chota and Shibuki's visa was about to end. They enters the game venue - botanical garden, difficulty level - 7 ♡, game name - Hide and Seek, game characters - Sheeps and a Wolf
They find some tools and chokers on a table. After taking the equipments they enter the arena, where the rules are explained. Chota becomes the first Wolf, he looks at Arisu and he becomes the next. They realize there's no reason for the sheeps to hide. Arisu looks at Shibuki and the wolf is passed to her. Shibuki tries to run away with the wolf Karube stops her and asks her to look at him and threatens her with an Axe. He puts the Axe down to choke her when she takes it and hits him. Karube gets injured and lets her free she unitentionally looks at Chota, the wolf passes to him. He starts runing with the wolf role and Arisu follows him. He looks at Arisu and the roles again gets changed. Arisu asks for an apology, Chota breaks off their friendship and Arisu starts running away, when suddenly everyone stops trying and communicates through the choker, recalling their friendship days, they discuss their dreams and realizes for them a friends life matters as much as their own. Shibuki says eventhough she wanted to live she can't shoulder the burden of all the lives. Arisu asks everyone to show up but everyone gives up and hides well. Karube asks Alice to look for the beach, he might get an answer there. The time gets up, coker of the sheeps blow off killing them. Arisu grieves at his friend's death and returns to the enterance.
"Game Over" Prize " Sheep Mutton"
Finding the Beach
Four of Hearts
Stealing the Cards
10 of Hearts
Arisu, Kuina, Usagi and Chisiya went outside and saw a broadcast From the Borderland citizens, Saying the 2nd phase is about to commence, After finding Tatta, The King Of Spades starts shooting. They arrive at the King of Clubs venue.
King of Clubs
Third, Fourth, and Fifth Day of Exhibitions TBD
Seventh Day of Exhibiitons
Queen of Hearts
After returning to the real world, Arisu learns that his father and younger brother actually cared about him and watched over him while he was in a coma. He looks at the screen listing the victims of the meteor incident, and griefs over the death of Chōta and Karube. He asks his brother to mentor him, if there was just one college, any college, that might accept someone like him. His brother smirks and agrees. Later, he reunites with Usagi in the hospital. He awkwardly went with the flow and asked her out for a date while feeling a strange bond. They fell in love and the two eventually marry and Arisu also begins mountaineering under Usagi's guidance. Arisu gets accepted to college and studies psychology.
Now a licensed clinical psychological counselor, Arisu works in a school to help out students with psychological issues. While returning from a seminar in Shizuoka, he receives Usagi's phone call that she is entering labor. Rushing through Tokyo under the storm, he is hit by a fallen billboard alongside 5 other people, and they are sent to the Borderland together to participate the Nine of Hearts game.
When he arrived in the Borderlands again, he regained all of his memories for when he last was there and managed to understand how the game works. His wife and their newborn are the driving forces of Arisu to depart the Borderland for a second time.