Hikari's personality is simply unpleasant, being rude, domineering, and extremely full of herself - and the System and how rapidly she's risen through its ranks has done almost nothing to alter that, in fact it's made her even more egotistical and cruel to others, and she highlights a sense that because she's the best of her class she is, in effect, the ruler of it, being able to do whatever she wants without any thoughts or concerns over the other students within the classroom at all, instead seeing them as victims or monuments to her own vanity depending on whether they're in her social circle or not - with a special toxic attitude to [PROTAG] and her group, who she seems to want to antagonize whenever possible. It's unclear why she is so especially focused on them, but it's possibly a remnant of the fragment's original purpose of a dating sim, where she'd be one of the classic bully NPCs that cause trouble for the protagonist and their relationships with the others in one or multiple routes - though this doesn't seem quite right, as she's incredibly focused on [PROTAG] herself, despite her not having been a romance option and just a friend who introduced the protagonist to the other girls in the original game. Hikari is extremely arrogant and confident in her abilities, and to be fair she has somewhat of a right to be, as she's the most skilled and easily strongest combatant of all the school's students in general, to the point oftentimes when she appears in an arc she deals with at least one of the threats extremely easily, such as when she effortlessly crushes Nossu and sends her to the aquarium, stealing [MAGE]'s thunder in the Monster Clan arc. She believes that her high level and superior skills are proof of her superiority compared to her peers, who just don't work as hard, and while there is technically a truth to that statement, her wealthy family has afforded her far more chances to improve her level than the other students, even the similarly wealthy Prince, owing to their connections with the prime minister. Despite this, she refuses to accept any criticism that her skill gain is artificially higher than the other students, and becomes increasingly angry and full of denial when anyone presses the issue, suggesting a degree of insecurity regarding her talent and potential that clashes with the rest of her character in many ways, though these responses become more chill and smug over time, due to unknown reasons. Despite this cruelty, she doesn't act especially rude to her clique of followers, even helping them train if necessary, though she becomes truly savage if she perceives any of them as having betrayed her, usually by not being quite as zealous when it comes to bullying [PROTAG] as her, though again these responses become more chill (but still venomous) over time throughout the story, with no major character development or events that would seem to make such a change natural. Overall, these changes are quite odd, and even [PROTAG] herself finds them inexplicable.