Mina comes from a religious and well off family. Growing up with a single mother, Mina was usually left to her own devices due to her mother working tirelessly to provide the best life she could for Mina. This would often leave Mina feeling very alone and yearning for some kind of attention. Due to her mother's job, it was common for them to move around, making things tough on Mina. By middle school, making friends felt pointless because Mina knew she'd be uprooted from the environment sooner or later.
As a student, Mina has always been one to keep to herself unless someone in particular catches her eye. She has always been the quiet type. Often times, Mina would draw in class to further keep to herself. However, doing such caused her to be a target for bullies rather often. Not only that, but students would also spread rumours about her using the knowledge of her moving from school to school.
Mina always did her best to ignore it all, but such acts only further pushed her to isolate. As a result, Mina continues to grow up being very asocial.
Meanwhile outside of class, Mina's mother constantly pushed her to attend sermons at church. Much to her dismay. Mina has never liked going to church, but her mother didn't give her a choice.
When it's time for high school, Mina follows the same routine of keeping to herself. And she half expects rumours to start, but to her relief, they do not. Her mother informs her that she will be staying at the same school for her entire high school duration. Mina doesn't believe her at first, but her mother promises— a thing she rarely ever does. Mina chooses to trust in her.
Time at Kosei High School feels refreshing even if the school ties to religion. Mina is able to attend the school through the art program. In the art program, she meets Yusuke Kitagawa who catches her eye right away due to his eccentric behaviour. The two hit it off pretty quickly and end up becoming very good friends.
However, Mina soon learns of Madarame and finds him to be rather suspicious. Even when she tries asking Yusuke about it— whether he believes that Madarame truly means what he says— she is quickly shot down. After the second time of asking, Mina doesn't bring it up again and instead cherishes her friendship with Yusuke. But during her free time, she does sleuthing of her own.
Mina learns what a fraud Madarame is, but ultimately feels hopeless since trying to talk to his previous pupils only led to dead ends. Mina desires to get Yusuke out of a situation where a shitty adult steals his ideas but has the audacity to call himself an artist.
Second Heist: Ichiryusai Madarame
By a stroke of fate or pure luck, Mina comes across the PhanSite. She's skeptical, but leaves a long post detailing how Madarame steals from his pupils and even steals ideas and artworks from her only friend. It feels desperate to post, but if the so called "Phantom Thieves" have a chance of seeing it, then she'll bet on said chance.
Days past. Then weeks. And finally, her posts catches the attention of the group which in turn has the admin of the site reach out to her. She responds immediately and agrees to meet up to share more of her findings. At the Shibuya station, she mets Joker, Ann, and Ryuji. She shares everything, including her concern for Yusuke. She then bows and pleads for the phantom thieves to help her. They agree and swap contact information.
For the first time in months, Mina feels content knowing that Yusuke will get help from capable people. But... wait. Capable people? Mina wonders why she isn't capable of helping the one person that matters deeply to her. It makes her feel useless and worthless. Not only as a friend, but as a person.
Eager, she messages Joker saying that even if she doesn't understand how they do things, she wants to help. She doesn't feel right sitting by idly waiting for the Phantom Thieves to do something. She wanted to help out more. Of course, she was told that she couldn't. This frustrated her naturally, but she refused to leave it at that.
The next school day, Yusuke tells her how he was enthralled by this girl he saw in the train station. Mina playfully indulges in the conversation like she always does— asking for details on what the girl looks like. When Yusuke describes her traits that align with the very girl she met the other day, her eyes widen.
So when Yusuke later expresses excitement at having Ann as his model for a new art piece, Mina forms a plan to be at the place at the same time. Without either party's knowledge of course. Later on, from an alley nearby, she watches Ann, Ryuji, Joker and a .. cat? talk about some app calked the Metaverse and trying to find keywords. She's very confused and when she hears Joker's phone say "candidate found", in the utter blink of an eye, the world before her changes.
The Shack once before her was now some grand museum. She's so shocked by it that she cannot help but voice it aloud— alerting the Phantom Thieves to hear and see her. After telling her how dangerous it was to be in a place like this, they quickly ushered her out. Ryuji quite literally had to pull her along.
Despite being forced out of the Metaverse, when Mina opens her phone to try downloading some Metaverse app, she sees a strange new app on her phone with a creepy red and black logo. Curiously, she opens it and is prompted to enter in keywords. It must be fate. Mina entered the keywords she overheard and reenters Madarame's palace. The Phantom Thieves aren't by the entrance anymore, so she traverses by herself.
She manages to sneak by shadows with ease. Thanks to the Phantom Thieves entering before her, she doesn't encounter any shadows. Until she does due to somehow getting further along than the Phantom Thieves, and starts running for dear life. This alerts other shadows in the process and the scene looks both ridiculous and comedic.
Meanwhile the Phantom Thieves see how quiet it is all of a sudden. After a while, Mina is so out of breath that she has no choice but to land face first into the ground. She screams and braces herself for the worse. Instead, she's picked up a shadow and held up for Shadow Madarame to see. There's a remark of how she's somehow responsible for certain parts of security in the museum being toggled off. Shadow Madarame laughs as she struggles pathetically and makes a comment how it's similar to her pathetic attempts to report him. So he knew about that. Madarame goes along to say how she's a useless friend as well. And the only reason why he allows Yusuke to stay in contact with her, is because she inspires him enough which gets Madarame more claims over Yusuke's artworks and ideas.
The information is far too much to bear and Mina begins to blame herself for the situation Yusuke is in. She begins to believe it's her fault and caves into all the words Madarame feeds her. She's ready to give in and accept her fate when she hears a voice in her head. It tells her to not listen and give into the twisted desires of crooked adults because she knows better than to let people put her in a box. Telling her what she is and isn't. Blaming her for their mistakes and their hurtful words.
The feeling was all too familiar and that's when Mina knew she couldn't give up. Not here. Not now. What happened to her eagerness to help from earlier? Her mind was made up and the contract was sealed. Mina's persona had awakened.
After managing to defeat the shadows, Madarame gets away like the coward he is. Due to the weight of it all, she collapses. Eventually, the Phantom Thieves find her and she is carried outside of the Metaverse. Once she awakens, she is questioned. Mina explains everything, ending it with a "This means I can help now, right?"
The four look pensive, but Morgana says that they should probably let Mina join them that way she doesn't try wandering in on her own. From that point on, she becomes a member of the Phantom Thieves. She is able to quickly grasp all the rules of the Metaverse Mina is probably the first one to piece together that the mental shutdowns from the news sounds eerily similar to what Morgana explained could happen if things go south with taking a Palace user's treasure. However, she doesn't bring this up.
During their meeting, they mention the high security in the courtyard. Mina is quick to bring up the door in Madarame's shack that looks similar to the one she saw in the Metaverse. Morgana agrees and they devise a plan to get inside. Joker and Ryuji will wait inside the Metaverse while Ann, Morgana, and Mina will work together to get the door open and make sure Madarame sees.
The day of operation arrives. Ann is busy with Yusuke while Morgana and Mina focus on unlocking the door. The lock gives them both issues. Mina with her inexperience at lockpicking. Morgana with his paws while also trying to teach Mina how to lock pick.
Despite that, the door being open is a success. Ann pulled Yusuke into the room with Madarame watching and once the lights are on, Yusuke is surprised to see Mina there, but doesn't have the time to question her. Both Ann and Mina point out Madarame's lies not adding up which only results in Madarame threatening legal action. The four of them run away and make their escape in the Metaverse.
Ann falls as Yusuke's holders her while Mina's wings stop her from hitting the ground. The security inside the his palace was successfully shut down by Joker and Ryuji. After that, they do their best to escape as to keep Yusuke from danger, but of course, they're unable to exit without running into shadows and shadow Madarame himself. It is then that Yusuke has his own persona awakening. Of course, Mina hypes up every second of it.
After Madarame is defeated, Mina offers up her dorm room for Yusuke to stay in. But Yusuke brings up Kosei's dormitory rules. When Yusuke spends all of his money on treats to possibly give Ann's parents, Mina grimaces. She's the one that buys him meals for as long as he needs.
The hotpot party is used to celebrate the defeat of Madarame and a welcome party for Yusuke and Mina.
Third Heist: Junya Kaneshiro
Before it all begins, when Ryuji, Ann, and Joker talk in the groupchat about the things Akechi Goro said about the Phantom Thieves on live tv in the group chat, her stomach immediately drops. She's heard that name before. It's a name she's tried forcing herself to forget. She doesn't read the rest of the conversation. Instead she goes back to sketching in her notebook.
When Joker brings Makoto to the hideout, Mina can already tell she doesn't like her. She doesn't say much as Makoto technically blackmails them. But she does scold Ryuji for slipping up about their identities as Phantom Thieves.
When it's time to investigate into the mafia doing dealing in Shibuya, Mina does her part at Kosei High School to ask students if they know anything about shady jobs to take up in Shibuya. When her and Yusuke meet up to share intel, the two of them both conclude that the shady jobs relate to drug trafficking.
When Joker finds a name and the Phantom Thieves enter his cognitive distortion through the Meta Nav, Ryuji makes a comment about how Mina should be able to fly up to Kaneshiro's palace since she's a seraph and all. Mina only frowns and replies about how she doesn't think she's ever tried flying for that long to something so high.
The following day when before Makoto approaches them at the Accessway, Mina points out how they should be mindful because Makoto followed them here. When Makoto walks over, Mina can't help but roll her eyes in annoyance. She quickly makes a comment on how useless she must feel considering she's the student council president but can only present as somewhat useful when blackmailing others.
Mina is aware she sounds harsh, but she doesn't expect the others to chime in to agree. She can't help but smirk when Yusuke agrees. What she doesn't expect is for Makoto to go running off to do something idiotic. Mina groans in annoyance when the group is almost forced to go looking for her.
The confrontation with Kaneshiro annoys her deeply because this wasn't how things were supposed to go. Mina doesn't say a word as Makoto explains things from her perspective. She doesn't voice her disagreement for taking Makoto to the Metaverse.
The seven of them go up the bank. When Kaneshiro confirms Mina's suspicion of her being connected to Sae Niijima. She had a feeling when she first learned her name. Mina is more concerned with how the name coincides with yet another person being against the Phantom Thieves. The other notable person being Akechi Goro.
The heist in Kaneshiro's Palace goes along as planned. However after the battle is concluded and Kaneshiro starts sharing details about someone else using their access to the metaverse without a care for consequences, Mina knows that deep down, he's right. She already suspected the case months ago.
Nevertheless the group heads to Leblanc to open up the briefcase thanks to Makoto memorising the code. Mina is the first that points how the money in it isn't even real. After all, it sounded far too good to be true.
Much later when the group gets together to study, Mina sits next to Yusuke at the end of the table. Once they take a break to watch the TV, Mina hears that name again. Akechi Goro. She shakes her head because she knows it's a name she's tried so hard to forget.
But as soon as he hears his voice and sees his face, memories come rushing in like a typhoon. Mina feels sick to her stomach and immediately excuses her to use the bathroom. Being in the bathroom doesn't help as much she hopes however. She can still hear him speaking. The others figure that Mina is upset over Akechi labelling them as criminals.
Mina only leaves the bathroom once she hears the program has switched to a different topic. The others check in on her and tell her that Akechi's words are full of shit. Mina smiles nervously and winces at that name being mentioned again. The others note that Mina must REALLY not like Akechi. But Yusuke figures that there is probably more to it since he knows Mina so well by now.