As per wiki policy, spoiler tags can no longer be used on trope names. Therefore, spoilers below!
Hatsuka "Hazuki" JonouchiThe main character of the story. She grew up next to a wonderful family with three sons where she was friends with the youngest son. As of late, her parents died in a car accident, leaving her without a home or family. She's then taken in by her neighbor and has her parents' debt paid off by him.
- All-Loving Heroine: Even after she learns that her love interest is crazy, she still cares about him. The only exception would be in the Extreme Love End where he either kills the people in her life or her.
- Big Brother Attraction: Even though Shion is supposed to be her new big brother, she starts to develop feelings for him. During her confrontation with Kujo, he points out that she sounds like she's defending her boyfriend more than her brother.
- Conveniently an Orphan: Both of her parents die in the prologue. This leads to her getting adopted by Toji, giving her three brothers who all want to pursue a relationship with her.
- The Ditz: In Ryo/Ryusei's route, she bumps into Ryusei twice.
- Featureless Protagonist: Her sprites in the CGs don't add any special facial features.
- Happily Adopted: She loves her adopted family and is willing to pay back her adoptive father for his kindness.
- Hello, [Insert Name Here]: Like other visual novel characters, her name is changeable. However, her stage name will remain the same no matter what.
- Intoxication Ensues: In Shion/Toma's route, she drinks a lot of wine during a family dinner. When she wanders off to use the restroom, Ryo tries to take advantage of her drunken state.
- Nice Girl: She's so nice that people try to take advantage of her.
- Rose-Haired Sweetie: Her model has pink hair.
- Self-Deprecation: Rather than accept that Karen is insane or was pretending to be her friend, she believes that she deserved to be hurt.
- Stockholm Syndrome: It's possible that in Shion's Crazed Love End, she's developed this after being locked up for a long time. That or she's happy to be with him and doesn't care about her situation.
Toji JonounchiThe player's adoptive father and next door neighbor. He owns Chateau Entertainment and manages his sons' group, TERZETTO.
- Benevolent Boss: To everyone that works for him and not just his children.
- Death of the Hypotenuse: In Ryusei's Extreme Love End, he gets killed along with his family because they were perceived as a threat to Ryusei's relationship with the heroine.
- Disappeared Dad: To Ryusei. That's because Ryusei's mother was driven away by Toji's jealous wife.
- Mismatched Eyes: His right eye is blue while his left is green.
- Nice Guy: He cares a great deal about the heroine and is willing to help her as much as possible. He even shows his kind nature towards Kazuki, his other son.
- Parental Substitute: He becomes one for the protagonist, though it's less out of pity and more out of being that close to her.
Shion JonouchiThe eldest son and lead of TERZETTO.
- Beware the Nice Ones: He's one of the nicest characters in the visual novel , but he's also one of the more frightening Yanderes.
- Big Brother Mentor / Cool Big Bro: Depending on the route, he'll turn into this for the player. The latter can follow Shion/Toma's route with the player actually calling him "Big Bro", which could be derived from the Japanese term "Nii-chan/Nii-sama".
- Crazy Jealous Guy: He doesn't like seeing the heroine near any other guys, even if he is one of his own brothers. At one point, he tries to get her to wear a necklace he bought for her, hoping it would mark her as his and he insists that she belongs to him.
- Declaration of Protection: He makes this to the Heroine, reassuring her that he will look out for her.
- If I Can't Have You...: When the heroine tries to escape in his Extreme Love End, he strangles her to keep her from leaving.
- Love Makes You Crazy: While he wasn't always there, he becomes more insane as his route progresses. He eventually resorts to locking the heroine in a motel room in an attempt to finally have her all to himself. When she attempts to coax him into letting her go, he fails to understand that she's scared and insists that he's doing it to keep her safe.
- Mismatched Eyes: Inherited from his father.
- Perpetual Smiler: He's almost always shown with a kind smile on his face. When he turns Yandere, his smile becomes creepy and unnerving.
- Stalker with a Crush: In his Crazed Love End, he admits that he had been following her around and taking pictures of her since they were little.
- Stalker Shrine: It's heavily implied that he has one in his room, but the heroine didn't get a closer look at it. His Crazed Love End confirms that he has several pictures of her in a photo album, all which he took while following her.
- Well-Intentioned Extremist: He sees himself as this in his Deep Love End where he locks the heroine in a motel room just to make sure that no one else hurts her. Considering that she was attacked and almost killed in the Shion/Toma route, it's hard not to blame him for being scared that someone could kill her.
Ryo JonouchiThe middle son and the more flirty brother.
- The Casanova: He's notorious for his womanizing ways. Even when he's alone with the player, he tells her that he wants to be more than just siblings with her.
- Chuck Cunningham Syndrome: If the heroine chooses to pursue Ryusei, he will fall into the background. He's still mentioned, but he rarely shows up on screen after the choice is selected.
- Heroic Sacrifice: In his Deep Love End, he shields the heroine from a Stalker with a Crush who attempts to harm her for "spurning" his affections. This leads to him being permanently blind.
- Jerkass Has a Point: He tells the Heroine that Ryusei is hiding something from her. It turns out that Ryusei, a.k.a. Kazuki, is Toji's son, making him the half-brother of Shion, Ryo, and Toma.
- "Just Joking" Justification: He sometimes tries to cover up his flirtations by claiming that he's just teasing his new sister.
- Loony Fan: He has a group of them, all vying for his love. One of them tries to attack the heroine for being so close to him.
- No Sense of Personal Space: The Ryo/Ryusei route has his getting uncomfortably close to the player. She can choose to welcome it or push him away.
- Same thing applies to the Shion/Toma route, only the Heroine is less turned on and more afraid of Ryo's advances this time around.
- Stalker with a Crush: He reveals that he's always watching the heroine when she asks how he knows about Ryusei asking her out.
- Took a Level in Jerkass: Although he wasn't a saint in the Ryo/Ryusei route, he's far worse in Shion/Toma's route. He forces the Heroine in his room and tries to become as "intimate" with her as Shion was and almost takes advantage of her drunken state.
Toma JonouchiThe youngest son and the most serious brother.
- Childhood Friends: When he and the heroine were little, they used to hang out and spend a lot of time together.
- Childhood Friend Romance: This can happen if his Deep Love End has been obtained.
- Chuck Cunningham Syndrome: If the player chooses to pursue Shion, the heroine will perceive her attempts to repair her relationship with Toma useless and will give up on him.
- If I Can't Have You...: Implied with his Extreme Love End. The story just ends when he appears in the heroine's bedroom one night with a knife.
- Irony: He shares the same name with Toma who's also a Yandere love interest.
- Oblivious to Love: It's unknown if he's unaware that Karen has a huge crush on him or if he knows and isn't interested in her.
- Perpetual Frowner: He wears a deep frown on his face.
- The Quiet One: He rarely speaks, especially to the player.
- Sugar-and-Ice Personality: He's initially cold and distant towards the heroine, but then he warms up to her. That is, before the Yandere sets in.
- We Used to Be Friends: He used to be friends with the player when they were kids. However, for some reason, he stopped talking to her and ignores her.
- When He Smiles: On a few occasions, he lets a smile show to the heroine.
- You Gotta Have Blue Hair: He literally has this. This, along with his brown eyes, sets him apart from his brothers. He also has a bit of brownish-grey on one of his bangs.
Ryusei/Kazuki AkesatoA young pop star in the industry.
- Bitch in Sheep's Clothing: His route reveals that he had gotten close to the heroine so that he can get his revenge against Toji, who is his father. However, regardless of him using her, he's still intensely fixated on her.
- Freudian Excuse: His mother was a maid in the Jonouchi household and she was involved with Toji. She and Kazuki moved around quite a bit because she was afraid of Toji's wife who wasn't happy about her husband's infidelity. His mother passed away when he was ten and he was all alone.
- Knife Nut: His "Extreme Love End" involves him stabbing the Jonouchis with a kitchen knife.
- Love Makes You Crazy: More apparent in the "Extreme Love End" than the main route where he believes that the Jonouchi family are coming in between him and the heroine after she turns down his offer to live with him. In order to "set both of them free", he kills the family.
- Love Redeems: In a twisted sense. He doesn't understand how the heroine could still care about him after he attempted to use her for a revenge scheme, which he learned the hard way was unnecessary.
- Luke, You Are My Father: His route reveals that he is Toji's son, making him Shion, Ryo and Toma's half-brother.
- Mama's Boy: One of his scenes involved him talking fondly about the time he shared with his mother.
- Mismatched Eyes: Just like Toji and Shion, Ryusei has one blue and one green eye. He just wears contacts to cover the green eye up. This is because he is Toji's son.
- Murder the Hypotenuse: While he doesn't go through with it, he alludes to the idea that he would make Ryo "disappear" if he were dating the heroine. In his "Extreme Love End", he kills the Jonouchi family under the assumption that they're keeping the heroine and him being together.
- Nice Guy: He's the nicest guy in the novel. This is challenged in his route once it's revealed that he was trying to use the heroine in a revenge scheme.
- Secret Keeper: In the Ryusei/Ryo route, he learns that the player is the Jonouchis' adoptive sister. That's because he's trying to use her to get to Toji, his absent father.
- When He Smiles: While he's a bit of a Perpetual Smiler in his own way, he genuinely smiles when he and the heroine go to the planetarium.
Koshiro KujoThe Jonouchi family butler.
- Cassandra Truth: He knows that something is wrong with Shion, but if the heroine chooses to pursue a relationship with him, his warnings will be ignored.
- Long-Haired Pretty Boy: He has long brown hair tied in a ponytail.
- Peek-a-Bangs: His bangs cover half of his face.
- Poor Communication Kills: If he had taken the time to tell the heroine the reason why she should stay away from Shion, then the heroine wouldn't have been so resistant and Shion wouldn't have taken her to the motel where he chained her to the bed.
- The Stoic: He tends to wear a blank expression.
Karen ShinomiyaAnother pop star in the industry and is there specifically for Toma.
- Attention Whore: When Toma stops by to give the heroine a present (and to talk about their song), Karen desperately tries to get his attention.
- Bitch in Sheep's Clothing: In Shion/Toma's route, she acts super nice and friendly towards the heroine. However, when it becomes evident that Toma and the heroine have feelings for each other, Karen attempts to kill her on a couple of occasions. After a concert, she lures her to an empty hall to give her a "present".
- Clingy Jealous Girl: She doesn't like anyone getting close to her Toma. Only in Shion/Toma's route does she actually try to hurt the heroine for obtaining Toma's affections.
- Curtains Match the Window: Brown hair and eyes.
- Entitled to Have You: She feels this way towards Toma.
- Green-Eyed Monster: The reason why she's been trying to kill the heroine was because she had gotten Toma's attention, which Karen has been desperate to have.
- Loony Fan: She makes it clear that she's obsessed with Toma. At one point in one of the routes, she admits that she uses the same shampoo that Toma uses just so that she can smell like him.
- Murder the Hypotenuse: Toma/Shion's route reveals that she's been trying to kill the heroine for being near Toma.
- Never My Fault: Rather than accept that Toma has no interest in her or that she's doing something wrong, she tries to kill the heroine and blames her for Karen's insane jealousy.
- The Rival: For Toma's affections. She will go to extreme lengths just to have him all to herself.
- Single-Target Sexuality: She's very Toma-sexual.
- Walking Spoiler: She plays a big role in Shion/Toma's route, which is why some of her tropes are marked as spoilers.