The Main Character (aka MC) is one of the two human exchange students attending RAD alongside Solomon. Their default name is Yuki, however, the player can change this name alongside their birth-date at the start of the game.
Although MC's physical appearance completely depends on the player, the demon brothers have noted that they are kind of cute and hard to dislike. Asmodeus provides a few of MC's features in Lesson 8-15, such as their ring fingers being longer than their index fingers, and their ears being on the small side.
After the start of season three (Lesson 41), On the back of MC's hand there's a tattoo of three staves and seven stars, which symbolizes the Sorcerer's Society. According to Solomon, the stars represent the seven virtues: temperance, gratitude, chastity, humility, generosity, patience, and diligence.
MC's personality is determined by the responses and actions they make during the Main story, Event stories, chats, and calls.
However, due to the machinations of the game, MC is often considered nosy due to their tendency to get into matters that, at face value, appear to have nothing to do with them. This trait is often viewed as a detriment by other characters.
In Lesson 4-15, Lucifer commented that MC seems to be "the type of person that has trouble lying."
Mammon once lamented, during Lesson 16-A, that MC "may seem like someone who's really got it together", but has a "boneheaded streak", and that they can be "weak, and super reckless...and too damn gutsy". The recklessness is later confirmed, as they frequently choose to head toward danger rather than away from it.
It is implied in Lesson 17-7 that MC does well at card games. There is an option to downplay it, but Belphegor will believe they are only saying that because they felt sorry for him.
They have a tendency to be too overzealous when they enforce the pacts on the brothers.
According to Simeon, their greatest strength is being flexible and being able to adapt to almost any situation.
The majority of MC's background remains unspecified, with the only backstory being that they were picked randomly by Lucifer to be part of the exchange program at RAD. Apparently, they also had no knowledge of being chosen, for they were confused at appearing suddenly within the Devildom's student council hall.
While Lilith is eventually revealed to be MC's distant ancestor, neither they nor Lilith are genetically related to any of the seven brothers, by blood or otherwise. This is because — as angels that were created, not born — none of the brothers are related by blood to begin with. The brothers choose to see their relationships to each other as just that: brothers. This is also why Satan is considered one of the seven "brothers" despite the history of his creation.
Main Story and Events
The order of the demon brothers who made pacts with MC from first to last goes as follows: Mammon (Lesson 2-8), Leviathan (Lesson 4-6), Beelzebub (Lesson 6-10), Asmodeus (Lesson 8-15), Satan (Lesson 12-10), Belphegor (Lesson 18-19), and finally Lucifer (Lesson 20-14).
In Lesson 5-7 (Normal), it was revealed that MC's room is directly behind the kitchen. A large part of their room was also destroyed after Beelzebub destroys the kitchen wall connected to their room.
MC has so far developed kemonomini traits three separate times. The first was in We're All Bad Here, where they developed bunny ears after eating one of Simeon's cookies. The second was when MC has the choice of being a dog or rabbit as a game avatar in the Devilgram Animal Game. The third was in Lesson 53, when MC was magically given a sheep's tail to play the game Tail Thieves.
In Lesson 41, MC was revealed to be studying the magical arts with Solomon serving as their teacher. From Lesson 45 onward, MC underwent seven trials to earn their sorcerer's license. By the end of Lesson 58, MC officially became a sorcerer, though they are still under Solomon's apprenticeship. In Lesson 62-19, Lucifer states that there are probably only a few demons who could pose a threat to MC due to how powerful they have become. In Lesson 64-17, MC was able to successfully teleport themself and Beelzebub despite it being the first time they teleported more than 1 person. In Lesson 70-17, MC was able to summon Lucifer into the Human World which requires a large amount of magical power. In Lesson 74-17, MC was able to accurately summon Lucifer into Raphael's dream world even though the paths to the dream world are very unstable.
In Lesson 62-17, Diavolo asks MC to become a student council officer. However, there are demons that are against MC becoming an officer since no human has ever become an officer before. Therefore, Diavolo asks MC to complete a preliminary task to prove their worth before doing the 3 trials that are required to become a student council officer. If MC failed the preliminary task, then their status as an exchange student would also be revoked. The preliminary task involved MC finding a specific card imbued with magic amongst all the fake cards scattered around RAD. Throughout Lessons 62-64, MC finds various fake cards, but MC finally successfully finds the specific card that Diavolo hid after getting some hints from everyone. In Lessons 65, MC begins the 1st trial of becoming a student council officer. Diavolo tasks MC to work together as a team with the new exchange students, Thirteen and Raphael, for the RAD Sports Festival. In Lesson 66, MC completes the task after all 3 of them work together to defeat the chimera that was summoned after Mammon threw a grimoire on the ground which contained a magic seal for summoning a chimera. In Lessons 71-72, MC is told to compile a report on how the demon students view the exchange students and interview the exchange students in regards to their experience at RAD. However, this is a cover for the true 2nd trial which was for MC to solve one of RAD's problems out of a genuine sense of caring instead of being told to solve it. MC and Mephistopheles end up solving the mystery, so MC passes the 2nd trial.
In Lesson 77-9, MC is given the final trial to become a student council member. MC is given the task of figuring out and fixing the situation regarding the bulletin board that grants the wishes of those who post a wish on there. They are given 3 days to solve the problem. Later, MC and the brothers discover that the wishes only come true when they are posted online while at RAD. MC then remembers one of their sorcerer lessons with Solomon and realizes that a magical item that contains a spell is causing all of these wishes to come true. In Lesson 77-19, all the brothers are helping MC look around the RAD campus for the magical item, but they can't find it. MC suggests that the magical item might be hidden inside the RAD bulletin board. Lucifer mentions that the newspaper club is in charge of managing the online bulletin board, so they decide to visit the newspaper club the next day. In Lesson 78-4, it is Day 2 of the trial. MC visits the newspaper club and asks Mephistopheles to take the bulletin board offline. Mephistopheles tells MC that he can't access the admin menu because something keeps rejecting him when he tries to submit the password. MC senses a strong magical power from the computer and speculates that the magical item is embedded inside the newspaper club's main computer. In Lesson 78-7, MC recalls another one of Solomon's sorcerer lessons. In his lessons, Solomon taught MC how to embed a magical item into another object and how to remove the magical item from an object. In Lesson 78-9, MC tries to remove the magical item from the computer using the method Solomon taught them. This method involves condensing magical energy into a ball and pushing it into the object in order to force the magical item back out. MC's attempt fails because they didn't push enough magical energy into the computer. Solomon speculates that this magical item must be the type that stores magical energy each time it is used. So, the magical item became more powerful after granting all those wishes. MC then has all the student IDs, except for the ones belonging to the student council members, locked out of the computer system in order to prevent the magical item from gaining more power.
In Lesson 78-11, some odd things start happening to Asmodeus, Levi, and Mammon. Asmodeus has a missing reflection, Levi becomes invisible, and everyone forgets Mammon's name. In Lesson 78-17, Solomon speculates that all 3 of them are under the influence of the dark crevasse (from Lesson 76) that pulled them in. The dark crevasse is basically a black hole that has the power to eliminate whatever it swallows. So, all 3 of them died when they were swallowed by the dark crevasse, but Barbatos revived them by using time manipulation magic. The dark crevasse's influence was stronger than they thought, so it is affecting the 3 of them. Therefore, it is necessary for them to sever themselves from the dark crevasse or they will cease to exist. Everyone is worried since this is the final day of MC's trial and they also have to solve this problem. In Lesson 78-19, MC has an idea to post a wish on the RAD bulletin board to return Asmodeus, Levi, and Mammon back to normal, but it doesn't work. The post would delete itself as soon as they uploaded it. Belphegor then comes up with a way for MC to pass their final trial, that is, to throw the magical item inside the dark crevasse. MC also comes out with an idea of how to extract the magical item from the computer after they see Satan send Lucifer a text message with a cursed attachement. In Lesson 79-1, MC explains that their idea is to infect the bulletin board with a virus to create an opening in order for them to remove the magical item. In Lesson 79-9, the computer is infected with the virus and MC tries to extract the magical item again. They are successfully able to do it this time and the magical item turns out to be a gigantic treasure chest.
In Lesson 79-11, Asmodeus, Levi, and Mammon become invisible. Barbatos' face also looks pale. Solomon speculates that dark creavasse must have also affected Barbatos since he had revived the 3 brothers after they were pulled into the dark creavasse. In Lesson 79-14, they plan to throw the magical item into the dark crevasse. Beelzebub, Belphegor, Raphael, and Luke go to gather the ingredients for creating one. However, MC receives a message from Raphael from Belphegor's D.D.D. requesting for help. MC teleports themself and Lucifer to their location. It turns out that the issue was that Beelzebub was trying to eat all the ingredients since he was hungry. Afterwards, MC was able to transport Beelzebub, Belphegor, Raphael, Luke, Lucifer, and themself back to RAD all at once. All of them then head to the courtyard to create the dark crevasse. In Lesson 79-19, the dark crevasse is preventing the magical item from being pulled in because it wants to pull back in the 3 brothers that had been swallowed by it before. So, it focuses on pulling the 3 brothers in. In Lesson 80-2, Lucifer transforms into his demon form to prevent them from being sucked in. MC then has the idea to open the treasure chest (the magical item). In Lesson 80-4, Diavolo reveals that the key to unlocking the chest is for the lock to scan the iris of his eye. He explains that the lock is connected to his magical energy and that it reads his magical energy by scanning his iris. Diavolo scans his iris and the magical energy stored inside the chest is released. The released energy is pulled inside the dark crevasse and the crevasse disappears.
In Lesson 80-6, Diavolo reveals that the magic item was hidden within the bulletin board as part of RAD Gets Prank event. A student is randomly chosen to plan and execute a practical joke that affects all of RAD. The student must also get permission from Diavolo by explaining what they plan to do and how they plan to execute it. There is also a rule that all the student council members should notified about the prank. However, the rumor about the bulletin board started spreading faster than expected and things started going downhill. So, Diavolo thought that it would be a perfect challenge for MC's final trial which meant that he had to keep it a secret from all the brothers. Diavolo then tells MC that they passed the final trial.
Because MC's relationships vary depending on the player, this section is for listing moments or interactions with MC and the other characters that are both immutable and noteworthy.
- In the Dark Santa Pop Quiz, Lucifer gifted MC a rose from a completely new genus which he crossbred himself, using magic so that the rose wouldn't wilt for a year.
- When teaching Seductive Speechcraft to MC in Lesson 29-7, Satan was easily seduced by them when they meowed cutely.
- A similar moment occurred in Lesson 46-7 if MC chose to put on cat ears to battle Satan in the RPG Devil's Quest.
- In Lesson 31-32, Asmodeus asked MC to help him win the bloody moon competition. He was very grateful for MC's assistance, and stated that MC gave him new insight about himself (and Lucifer).
- This is the first Shall We Date game where the MC isn't exclusively female.
- Depending on the player, MC may be any gender, and is identified using they/them pronouns in game.
- In the first draft of the game, MC was originally going to be a high schooler employed to babysit the seven brothers (under the guise of humans) at the House of Lamentation in the human world. 
- At the time, MC was written as female, which left some leftover pronouns that were corrected after the game was released.
- MC also would have had a mother who's an artist, and one of the art pieces was in Diavolo's possession. 
- In Lesson 41, this plot was reused as a cover concocted by the brothers (mostly by Mammon and Asmodeus) to surprise MC when they were staying in the human realm during their vacation.
- MC appears in the Another Cat Person card as a cat.
- This is the first time MC has appeared on any card.