5. also, it's literally entitled "Pandora's Heart". if i'm not mistaken, she was the first human woman in greek mythology and she had this box entrusted to her. she was warned not to open it. but because she was curious, she neglected the warning. when she opened it, several dangerous monsters (7 sins) were released and spreads out to bring chaos in the world.
this is similar to the comic, whereas pandora was baited by her curiosity, the characters was drowned in their temptations. both releasing demons as a result.
box = heart
pandora = the changed
7 sins = demons
this also hinted that their changing might be related to the 7 sins. no 15's suggesting that it might be wrath. although he is cute and wholesome, the cover proves he can be dangerous. also, he changed because of the riot and a panel of him all shadowy was kneeling and mourning beside his mother's body. my theory is, he might've changed out of anger because of her death thus, wrath.
ALSO DARK COZ THEY LITERALLY SHADOWS
i didn't expect such cute and wholesome interactions because the cover is a bit misleading (maybe not). the cover suggests that it is a pretty dark manhwa (which is kinda true btw) with the main element being a toxic relationship between the two protagonists.
more key points solidifying the fact that it is really dark:
1. demons — although it could've just been a fantasy element but the concept of "demons coming from the human heart" is relatively dark. also, it projects the darker side of our emotions & desires. although we don't have supernatural stuffs with it, you can't deny the fact that people can become their own demons when they succumb to their desires.
2. quarantine facility — “you can't go out anymore" they're pretty relaxed there, you can't deny the fact that they're imprisoned in there for their whole lives. the squabble between rex and zach, also no. 15's past (riot) suggests that it's a mistake and not very safe for the people inside to be clumped together. since their demons could take over them for some period of time (as an effect of their changing), any moment would've started another riot and it would've been chaotic.
3. harassment — louis was immediately bullied and harassed upon his arrival to the facility. in addition to that, he was almost raped. although there are still good guys in the facility, you cannot deny that there are still plenty of bad guys in there. they all became demons for a reason, you know — bruce's changing proved that.
4. corruption — bruce's father obviously pulled the strings using his position in order to cover up his son's changing and the information about the master key. he's framed someone for his benefit.
I HAVE LISTED ALL THESE BUT INSTEAD OF GETTING CHILLS WHOLE READING THIS ALL I DID WAS SMILE LIKE AN IDIOT BECOZ THEY'RE TOO CUTE AND ADORABLE.