The Main Character (MC) is one of the only two human exchange students attending RAD. 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 does provide a few features of MC, such as their ring fingers being longer than their index fingers, and their ears being on the small side.
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 Simeon, their greatest strength is being flexible and being able to adapt to almost any situation.
The majority of MC's background remains unknown, 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 at the Devildom's student council hall.
Mammon, Asmodeus, and Beelzebub are the only brothers to not have transformed into their demon form in a fit of rage against MC. While Beelzebub did demolish the kitchen due to MC eating his custard, his target was Mammon. Leviathan, Lucifer, Satan, and Belphegor have tried (and succeeded, in Belphegor's case) killing MC in their demon forms, albeit for different reasons and at different times.
Initially portrayed as the disembodied voice MC occasionally hears, Lilith is later revealed to be their distant ancestor. She also reveals that she specifically chose MC to influence and encourage in order to fix the familial problems of the demon brothers - in particular, the rift between Belphegor and Lucifer, and also brought their photo to Lucifer's attention making him choose them for the exchange program.
Despite Lilith being their ancestor, neither they nor Lilith are genetically related to any of the seven brothers, by blood or otherwise. This is because none of the brothers are related by blood to begin with. They were all created, not born (in a human sense). This is also why Satan is considered one of the "brothers" despite the history of his creation.
- 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.
- MC has so far developed kemonomini traits three separate times.
- The first is in We're All Bad Here, where they developed bunny ears after eating one of Simeon's cookies.
- The second is when MC has the choice of being a dog or rabbit as a game avatar in the Devilgram Animal Game.
- The third is in Lesson 53, when MC is magically given a sheep's tail to play the game Tail Thieves.
- In the first draft of the game, MC was originally going to be in high school employed to babysit the seven brothers (under the guise of humans) at the House of Lamentation in the human world (which would be set in the English countryside)
- They wouldn't have discovered the demon's true identities until the second half of the story. 
- At the time, they were also written in mind as female.
- MC also would have had a mother who's an artist, and one of her 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.
- In Lesson 5-7 (Normal), it is revealed that MC's room is right behind the kitchen. A large part of their room was also destroyed after Beelzebub destroys the kitchen wall connected to their room.
- 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).