All-Loving Hero: The Snark Knight he may be, but Usa is friendly to everyone, even those who he has no reason to. Though that won't stop him from calling them out on their behavior.
Butt-Monkey: Tends to be a frequent victim of Mayumi's pranks, and Ritsu's wooden sword, as well as her Brutal Honesty.
Cannot Spit It Out: Manages to be both this and a Dogged Nice Guy. Justified example too, as it's made clear that even if Ritsu is in love with him, she'll likely reject him simply out of her anti-social behavior. It's only after she defrosts that there's any chance she might say yes.
Character Development: At the start, Usa is the Only Sane Man who's totally bewildered by the rest of the residents and even those outside of it. Over time, he becomes more and more unfazed by the situations he faces whereas outsiders act bewildered. Additionally, his interactions with Ritsu become more natural and genuine as he continues to reach out to her, eventually learning to share each other's interests wholeheartedly. See Dogged Nice Guy for more details on that.
Clueless Chick-Magnet: Has three girls his own age into him, and even Mayumi is implied to be searching for a man similar to Usa, though not Usa himself due to the obvious age difference.
Deadpan Snarker: Being around so many zany people tend sharpen a person's tongue.
Dogged Nice Guy: A Decon-Recon Switch of the idealistic variant and a justified example. Ritsu doesn't take kindly to any overt romantic (or sexual) gestures or interaction due to her anti-social nature. It's directly stated that due to Usa's patience and kindness that she's able to trust him enough to get closer and closer, eventually falling in love with him. As Ritsu had other admirers who tried but didn't have the patience. The Deconsturction comes in when he ends up pestering her too much to her annoyance thanks to Sayaka's manipulation. Causing Ritsu to lash out at his behavior and get fed up with him. The Reconstruction occurs when he ends up realizing the error of his ways, leading to him learning to give Ritsu her space and not be clingy. Allowing her to not be the center of his world, nor him be the center of her world. His patience, kindness, and understanding nature allows him to win Ritsu's heart in the end.
Extreme Doormat: At least initially. Best seen while at work while the customers mistreat him. However, this seems to only apply to himself, in that he'll stand up for others without hesitation like Hayashi and Ritsu, but not for himself. Though to be fair, he does stand up for himself most other times, but Usa being Usa, he usually doesn't succeed. He gradually outgrows this though.
Nice Guy: He's too nice for his own good. This is how his eccentric classmates flocked to him in the past.
Only Sane Man: He's the only normal person in a building full of eccentric people, and has had to deal with eccentric classmates with unique quirks back in middle school. This trait actually lands him a job set up by a Sumiko and her friend.
The Snark Knight: He reaches this status due to many of his barbs being aimed at himself almost as frequently as every other character. Despite that, Usa is without a doubt a Nice Guy with high standards of decency.
Unfazed Everyman: Slowly becomes more and more at ease and comfortable with the rest of the residents and their antics.
Weirdness Magnet: It's the reason why he was called Freak Show at school in the past. His Nice Guy status is the likely explanation as for why so many quirky people end up being drawn to him.
Brutally Honest: She has a habit of being too straight with people, and it can lead to hurting another person's feelings.
Dandere: She's quiet and standoffish to pretty much everyone. Thanks to Usa's efforts, she mellows out.
Character Development: Goes from an anti-social bookworm to someone who's more open emotionally and branches out her interests such as playing videogames with Usa. By the end, she has a much wider circle of friends than she did at the start.
Endearingly Dorky: Lamp-shaded by Usa. She can be a really big dork, and it's adorable.
Deadpan Snarker: She apparently got from Sumiko, to Shiro's delight.
Defrosting Ice Queen: Initially very distant and aloof to everyone. Then she becomes more open and warm, making many friends along the way thanks to Usa's influence.
I Just Want to Have Friends: Defied. She says she's okay with being alone, but that doesn't mean she wants to completely alone, and does want some companionship.
No Social Skills: Outright stated by Usa to be anti-social. Episode 3 shows her trying to apologize for bluntly rejecting Usa's offer for a bike ride, but after a while she starts rambling, eventually leading her to clearly wondering why her words aren't coming the way she wants them to.
Only Sane Man: Subverted. She turns out to be Not So Above It All. Next to Usa, she initially seemed to be the only normal person in a building full of eccentric people. Only for her anti-social behavior and fixation on books to make her come across as just as weird as everyone else, just less so.
Shrinking Violet: She comes across as cold, but she's actually shy.
Sugar-and-Ice Personality: Initially, she's often aloof and seems disinterested, except when something regarding books is mentioned or laughs at Usa's jokes.
When She Smiles: A smile certainly suits her better than the usual blank expression.
Butt-Monkey: Shares this with Usa, but Shiro enjoys it thanks to his masochism.
Chivalrous Pervert: He's a perverted masochist, but is still a nice guy. He's also quick to voice his dislike of molesters, and treats Chinatsu's Precocious Crush on him like a phase she's going through.
Cool Old Guy: Probably the second oldest person living in the Kawai complex, and despite his perversion, he does share a few words of wisdom to the other tenants.
Hidden Depths: Dude's a writer. Specifically he's secretly Ritsu's favorite author, not that she's aware.
Berserk Button: Anything involving relationships or Sayaka.
Buxom Beauty Standard: Her well-endowed figure often makes others attracted to her and is frequently emphasized by her cleavage-heavy clothing.
Drowning My Sorrows: She frequently gets drunk on alcohol when she gets dumped.
Fool for Love: She'll often say Silly Rabbit, Romance Is for Kids! and try to crush their dreams. But the moment an ex or admirer of hers shows any interest, she drops everything and willfully ignores reason and logic.
Jerk with a Heart of Gold: She's fond of teasing Usa over his crush on Ritsu, but she still acts as sort of Cool Big Sis to him when the situation calls for it.
Ms. Fanservice: The only attractive thing about her is figure. Can't say the same thing for her personality.
Shameless Fanservice Girl: A Deconstructive Parody of the archetype, as Usa is at first attracted to her physically, even despite her wretched personality. Few episodes in, and because she's always showing a lot of skin, Usa is literally unfazed and has gotten used to her appearance. Not helped by her childish behavior being a complete turnoff.
Absurd Phobia: She's scared of cute and cuddly rabbits.
Bitch in Sheep's Clothing: Acts sweet and innocent, but her hobby is seducing men and then bumping them after a while.
Hidden Heart of Gold: She cares about her childhood friend, but tries very hard not to show it.
The Fake Cutie: Initially set up to be The Cutie to Mayumi's seductress, but is shown to have just as abhorrent a personality as Mayumi, and perhaps even more so.
Troll: She's not even The Gadfly as what she says usually goes beyond bizarre and causing bewilderment. Instead she really loves getting a rise out of Mayumi, either by bringing up her relationship issues, or groping her. It's not the riling up of others that she enjoys, it's the suffering.
