Apologizes a Lot: Marin’s always apologizing for reading people’s thoughts. Lampshaded in a string of apologies between her and Lucan.
Masculine Girl, Feminine Boy: Although Marin is not entirely masculine, she seems so next to the very feminine and girlish Haruhi; it helps that Marin used to be very boyish (complete with boyish haircut) as a child. Ryuu lampshades this.
Naïve Newcomer: Marin has no idea where to go the first day she’s at school. If you’re not paying attention, she also forgets her class number.
Brutal Honesty: Kaius doesn’t pull his punches in criticizing Marin.
Energy Blasts: Kaius’s psych, which activates whenever he feels strong negative emotion.
Glowing Eyes of Doom: Kaius’s blue eyes get brighter and sharper when he’s angry.
Jerk with a Heart of Gold: Kaius has a rude personality, but Marin finds out that he also has a motherly side when she discovers that he has been caring for orphaned kittens.
Jerkass: Ryuu even calls Kaius this verbatim at one point.
Kindhearted Cat Lover: Kaius has a soft spot for kittens. Also for cats when he and Marin adopt one together.
Loners Are Freaks: The school’s perception of Kaius, since he refuses to talk to anyone, takes mostly private classes, and doesn’t reveal his psych to anyone.
Power Glows: Kaius glows bright blue when he’s using his psych.
Psychotic Smirk: Kaius flashes one of these before he beats up the thugs trying to rape Marin.
Red Oni, Blue Oni: Kaius is the Blue Oni to Ryuu’s Red Oni, resulting in a lot of fights between the two.
Superpowered Evil Side: Kaius’s personality seems to shift into this when he uses his psych, regardless of whether he actually really has an evil side.
Attention Whore: Ryuu’s very photogenic, and loves the attention he gets from his fangirls.
The Charmer: He's generally a very friendly, outgoing and flirty guy.
Don't You Dare Pity Me!: He doesn't tell Marin about his heart condition because he wants her to treat him normally and not as someone to be pitied.
Heavy Sleeper: Despite Lucan’s best efforts to wake him, Ryuu can sleep through being hit, being splattered with water, and having heavy objects thrown at him.
I Just Want to Be Normal: Ryuu doesn’t want to be treated as different, even if he has a life-threatening heart condition.
Keet: Ryuu never seems to run out of energy or smiles.
Lethal Chef: When Marin tastes the bento that Ryuu made, she notes that the meat is overseasoned, undercooked and practically raw. On the contrary, Ryuu thinks it’s delicious.
Manchild: Ryuu has a few of these tendencies, such as his enthusiasm at getting to play in the rain or ride the swings at the park. His excuse is that he never got to do those things as a kid because he was either at home or in the hospital.
No Sense of Personal Space: Ryuu has just met Marin, but he’s very friendly and never misses a chance to tease her about being romantically involved or get physically close to her in some way.
Power at a Price: The reason why Ryuu faints so much is because he does not have enough energy to teleport as often as he would like due to his heart condition.
Sincerity Mode: When he confesses to Marin, she doesn't take him seriously at first, assuming that he sees her as just another conquest. It isn't until later that she realizes how much he cares.
Stepford Smiler: He's very good at hiding his insecurities and health problems underneath his carefree disposition. It's most noticeable when he forces himself to smile after Marin initially rejects his love confession.
Big Brother Instinct: Lucan has four younger sisters, so taking care of Marin comes naturally to him.
Big Man on Campus: Lucan’s the most popular guy in school, has his own Unwanted Harem and definitely qualifies as one of The Beautiful Elite. It's deconstructed on his route when it's revealed that he's actually terribly insecure, and the main reason he's so popular is that he unconsciously brainwashed the girls around him into loving him out of fear of being alone.
Nice Guy: He's consistently sweet, awkward, and an overall gentleman towards Marin. Unless Marin rejects him after she learns about his dark secret. Then he becomes not so niceanymore.
Not Good with Rejection/Yandere: If Marin rejects Lucan after she learns about his unintentional brainwashing of multiple girls, he intentionally brainwashes her into forgetting this and becoming as mindlessly devoted to him as his fangirls. Marin's profile even gains Mind-Control Eyes after he does this. Brrr.
Pretty Boy: More so because of his slightly longer hair and his acknowledged pretty boy looks in-universe.
Psychotic Smirk: Lucan has a secret creepy smile that really freaks out Ryuu.
Sweet Tooth: Lucan only eats desserts for his meals.
Telepathy: Lucan found out that he was born with two psychs. This is the other one, although it’s less hearing other people’s thoughts and more Mind Control.
Butt-Monkey: In-universe, Ruiko seems to be this to the other students. She’s the target of their pranks, and all of her previous roommates requested a room change after having spent one day with her.
Fangirl: Ruiko is an avid fangirl of both Lucan and Ryuu. She even heads Lucan’s fanclub.
Childhood Friend Romance: Of the unrequited kind. Haruhi has feelings for Marin, but he hasn’t confessed them and she doesn’t seem to feel the same way about him. That is, unless you choose him over Kaius.
He Is All Grown Up: When Marin is expelled from Planets and returns home, she finds that Haruhi has finally hit puberty and has adopted a boyish image.
Why Couldn't You Be Different?: Haruhi’s parents wanted a girl instead, which is why he dresses like one to try and please them. Which they don't approve of, so they eventually disown him.
Oginuma
Amazingly Embarrassing Parents: When he first meets Marin, Oginuma insists that she call him Ogi-chan and conveniently mentions the fact that Kaius doesn’t have a girlfriend.
He Who Must Not Be Seen: In-Universe, he is also the principal of Marin's old school, but no one there ever sees him because he spends most of his time at (P)lanets.
Older Than They Look: Marin comments that Oginuma looks more like Kaius’s brother than his father.
Open-Minded Parent: Oginuma is oddly encouraging when he realizes that Kaius and Marin are a couple, going so far as to encourage them to have sex after their first date.
Renaissance Man: Oginuma has mastered almost all of the psychics's powers.
