Big Heroic Run: Kou's fondest memory of Futaba is literally her chasing him (to save him). He even considers her as a heroine.
Damn You, Muscle Memory: In chapter 5, Futaba was supposed to take the train that would take her to the bus for the leaders' training camp. Instead, she accidentally takes the train she normally takes to get to school.
Does Not Like Men: In the prologue chapter, Futaba really didn't like boys. Part of why Kou caught her attention was because he hadn't hit puberty at that time and was thus "different."
Played by: Yuuki Kaji (anime & drama CD), Masahiro Higashide (film)
Kou is Futaba's First Love from middle school until he transferred school without notice. Upon re-entering Futaba's life, he's become jaded.
Brilliant, but Lazy: Kou is very academically gifted, and actually spent the majority of his middle school years studying. However, after his mother's death, he loses a lot of his motivation. When Futaba first meets him again in high school, he was in the advanced program until he drops back into the mainstream program.
Broken Bird: The divorce of his parents and the death of his mother have shaken Kou up rather tremendously, so much that Futaba barely recognizes him when they reunite.
Dark and Troubled Past: Kou's parents get divorced when he is in middle school, and he spends the majority of middle school studying so he could get a good job in the future to support his mother, so much that he wasn't able to spend much time with her himself. Then she dies.
First Love: One of the first things official material loves to point out about Kou is that he plays a big role in Futaba's life as her first love.
Grumpy Bear: Out of the group, Kou is the most reluctant to participate in their plans.
Jade-Colored Glasses: In flashbacks of Kou's middle school years, he generally seemed relaxed and got along with everyone (if not a bit shy). After his mother dies, he loses a lot of motivation in school, family, and even social life.
Jerk with a Heart of Gold: Kou often says things to Futaba that are downright pessimistic, but he really does care about her and tries to see her plans through.
Parental Abandonment: Kou's parents divorced when he was in middle school, and all he had left was his mother, who later died. Subverted in the fact that when Kou moves in to live with his father and brother, his family really tries to be there for him, but he's still uncomfortable around them.
Solomon Divorce: When his parents divorced, he went to live with his mother.
Sour Supporter: During the camping trip, he's the least excited about the activities.
Stepford Smiler: Kou laughs and jokes around his classmates, but only Futaba and Kominato really see his more unguarded moments.
Trademark Favorite Food: From his character file, chicken nanban (fried chicken seasoned with vinegar and tartar sauce).
Tsundere: Big time. This is even pointed out by Yuki Kaji and Maaya Uchida. He's a big type A, where he tends to act "pricky" (tsuntsun) and is secretly "deredere", like when he stood up for Futaba in the cafeteria.
When He Smiles: Kou seldom smiles, and when he does manage to laugh from the bottom of his heart, Futaba feels as though she's one step closer to seeing through his heart.
Played by: Ai Kayano (anime & drama CD), Izumi Fujimoto (film)
Yuuri is Futaba's classmate and shares a similar past of being liked by the boys and hated by the girls. However, unlike Futaba, Yuuri doesn't mind her unpopularity with the girls in the class. She later becomes one of Futaba's True Companions in high school.
Because You Were Nice to Me: Yuuri really wants the best for Futaba because she was the only girl in her class who didn't treat her with contempt.
Beware the Nice Ones: Yuuri is very protective of her friends and hates seeing them hurt. She also hasn't forgiven Kominato for taking her cupcake during the leadership training.
The Dog Bites Back: When Futaba calls out Asumi and Chie for treating Yuuri horribly, Yuuri counters them by humiliating them in front of the entire class.
Eating Lunch Alone: In the beginning of the story, Yuuri often ate lunch by herself outside in the cold weather.
I Want My Beloved to Be Happy: Yuuri gives up her crush on Kou, but it's really Futaba who she wants to be happy, as she treasures their friendship more than her crush on Kou.
Loners Are Freaks: Yuuri was ostracized by the girls in the class for being popular with the boys in the beginning of the story.
Lost Food Grievance: Yuuri doesn't get off to a good start with Kominato at first because he takes her cupcake during the leadership camp when she had planned on saving it for later. She's cool with him now, but is still affected by it, since she tells him off for doing it again during the school trip to Nagasaki.
Loners Are Freaks: In middle school, Shuuko was ostracized by the girls in class for sticking up for one girl who later did a Face-Heel Turn on her. Since then, she's never tried to befriend anyone and starts to hate school. In the beginning of the series, all the girls avoid her because she looks mean.
I Warned You: Kominato constantly warns Kou not to pay too much attention to Yui.
Large Ham: He can be this sometimes, especially when showing off to Shuuko. He's also able to say rather cheesy things and not be embarrassed.
Last Name Basis: Everyone calls Kominato by his last name, and the only time he has ever been called by his first name was from a family friend.
Loners Are Freaks: Surprisingly, for someone who's shown to have many friends in class, even Kominato has experienced this. When he was little, he was made fun of for crying a lot, and in high school, he even overheard some students complaining about his optimistic behavior.
Messy Hair: Kominato has naturally Quirky Curls. On one instance, Touma called him "Yakisoba head" (though since he was arguing with Kou at the same time it's unclear if he was referring to him, Kou, or both).
Played by: to be announced (anime), Yudai Chiba (film)
Touma is a boy from class 5 who crossed paths with Futaba during an Accidental Pervert moment. Seeing how good-hearted she is, he falls in love with her and dislikes Kou for allegedly playing with her feelings. He plays bass and provides backing vocals for his band.
Nice Guy: Touma is honest and considerate to people's feelings. His first appearance in the manga literally has his friends calling him a "goody-goody" for telling them not to eavesdrop on Futaba and Yuuri's conversation.
Solomon Divorce: When his parents got divorced, he went to live with his father.
Played by: to be announced (anime), Mitsuki Takahata (film)
Yui is Kou's friend from middle school when he moved to Nagasaki. She was once a Genki Girl and popular at school until her father's death has left her very disillusioned. This event naturally brings her close to Kou, who has gone through the same experience, and threatened by his relationship to Futaba.
Accent Tropes: Since Yui grew up in Nagasaki, she speaks in Nagasaki dialect.
Adaptation Dye-Job: Yui dons a pixie haircut in the original manga, but in the live-action film, her actress has long hair.
Birds of a Feather: Yui is drawn to Kou because their parents were hospitalized at the same hospital and because he's gone through the same lifestyle changes as her.
Broken Bird: Her father's death has changed her from being a cheerful girl.
Clingy Jealous Girl: Yui feels threatened by Kou's closeness with Futaba so much that she tries to make him stick by her at all times.
Jerkass Has a Point: Futaba gets on Yui's bad side when she basically tells her (in nice terms) that it's her fault that Kou is unhappy. Yui tells her (within reason) that she has no right to decide what she considers "best" for Kou.
Manic Pixie Dream Girl: She was the one who broke Kou out of his shell when he first transferred into her school.
Manipulative Bitch: Yui tries to stop Kou and Futaba from getting closer by guilt-tripping him to stay with her and forcing him to give up on Futaba. Subverted in the fact that Kou had known this the entire time, but still willingly went along with it because he felt sorry for her.
Parental Abandonment: Yui's parents are divorced. Dad died; Mom didn't want to take care of her. She now lives with her aunt and uncle.