Me's a Crowd: One of the things Heike can do with his powers.
Morality Pet: Nenene and apparently Toki are this to him. He treats Nenene kindly, takes care of her even after she's lost her power, and looks after Toki in compliance with her request back when she was still a Code:Breaker.
The Wonka: Considering his numerous eccentricities, habit of losing his cell phone, and tendency to disappear for days or weeks on end, it's a good thing that he's his own boss. Good for the Tenpouin Group too; without someone like him they probably wouldn't be nearly as profitable.
Eyepatch of Power: Later takes to wearing it much more often. It's revealed to be an effort to hide his right eye, which has returned to its original blue when his Joker power returned. The brown eye was Nenene's, whom he had already knew since then to be not his sister; he just didn't want to lose his bond as sibling with her.
Woobie, Destroyer of Worlds: When Saechika woke up from being exploded years later he vowed to "become justice and destroy evil even at the cost of others' lives" and declares himself the be "the ultimate victim, the only one who deserves forgiveness".
Innocent Fan Service Girl: She often does not seem to realize people are touching her boobs, that she is pressing them up against other people. She also allows another girl to constantly touch her breasts just so the other girl won’t be sad.
Cloud Cuckoo Lander: He threatened to blow up Ogami and Sakura's school but set of fireworks instead and decided they should get him a special lunch bread as part of a challenge. When they got the bread he gave it back to them as thanks... along with the bomb and the revelation that the school was specially built for Rare-Kinds and Power-Users.
Fire-Forged Friends: Makes the observation that only the threat of death could make Ogami & Sakura's group ally with the Code:Names.
Forgotten Childhood Friend: Met Ogami and Sakura when he was outgoing and friendly and she was a silent killer, respectively. He's also the one who really killed Ogami on December 32.
Humans Are the Real Monsters/Humans Kill Want Only: Kidnaps dozens of prisoners who've done horrible things and gives 100,000 high school students the vote on whether or not to kill them. They start voting "yes" mainly because they think it's a joke.
Hypocrite: They're the ones playing with people's lives...
Hypocrite: He believes that humans are evil for wanting to kill, but several chapters later questions why they don't just kill their enemies than play this game because "it would be more fun to kill them".
Face of a Thug: Despite his thug-like appearance, Kouji is a reserved and calm individual. Occasionally subverted in that once someone manages to get him to fight seriously, he becomes extremely violent and merciless with a sadistic grin.
Heel-Face Turn: Later joins Ogami's side as per Code:Seeker's dying wish.
Hidden Heart of Gold/Jerk Ass Facade/Knight in Sour Armor: Haruto's hired to kill a woman's stepson for the insurance and lets him go after the boy reveals he knew his stepmother's plans, claiming it doesn't matter to him/her if the boy lives. Between then and now Haruto acquired a little gang of orphans.
Yuki and Shigure's muggle best friend who's been in a coma ever since he tried to save Yuki from a falling building.
Weirdness Censor: It helps that (as far as we've seen) they've never been directly targeted and also Nenene is the daughter of the Prime Minister, who also happens to be the head of EDEN. They've recently been almost aggressively ignorant of the fact that the New Transfer Student goes by Ai Ueo (AEIOU), lined their school with explosives that turned out to be fireworks, forced Sakura and Ogami to get "Ai's" lunch, and suddenly IM'd them a "joke poll" putting over a dozen captured inmates' lives in their hands ("It is a joke, right?").
Bad Ass Family: They're ex-Yakuzas related to Power Nullifier and a powerful super-human-swordswoman who've been raising a little Power Nullifier whose blood can explode if mixed with Ogami's. Plus all those other (ex?) gangsters who hang around like adoring uncles.
Government Conspiracy: Is the head of the Japanese government and a secret government agency that uses (and makes) super-powered kids to kill other super-powered kids and non-powered baddies; he may also have some secrets of his own and he's a lousy father.
Jerk Ass: Was ready to disown Toki for being non-powered until Nenene gave half her powers to him. He was also ready to open Pandora's Box (the contained explosion that killed scores of power-users on December 32 that also contains her memories) just so Nenene could fight, or possibly trick Toki into fighting to protect his sister.
Mixed Marriage: Assuming he was actually married to Toki and Nenene's mother, and assuming they even have a mother.
Mood Dissonance/Slasher Smile: He has the gall to smirk at Hitomi as he (Hitomi) is on the verge of death and has a wider one when he's about to "wake up" Nenene.
Evil Twin: Though she's less evil than hellbent on accomplishing her tasks, which often require her murdering criminals in cold blood. And even her "twin" status is up to debate now.
Four Is Death: She was the previous Code:04, and lived up to this trope to boot.
Opposite-Sex Clone: To be precise, what she actually became to Toki. The original Nenene was neither Toki's twin nor clone and not even related to him by blood; she just belonged to the "Apple of Eden" group of children that Eden raised. In order to make a vessel for Toki's overwhelmingly powerful magnetism, her left brown eye was traded for Toki's blue one in order to imprint Toki's gene into her, thus transforming her into Toki's twin and the bearer of his inborn power.
Parental Favoritism: Prime Minister Fujiwara used to dote on her because she showed more potential with magnetism power than Toki. Which prompted him to run away from home, and in an effort to bring him back, Nenene shared half her power with him.
Sleep Mode Size: The current ditzy, amnesiac, loli self of Nenene is actually her Lost form. Her real self is not one to be taken this lightly at all.
The Mole: Implied to have been one to the Prime Minister by Saechika