Base-Breaking Character: Banri's original personality. Either people feel bad for him, because of the bridge incident screwing him over; hoping that somewhere down the line, things will work out for him, or he's a pathetic loser that can't move on from the past, and blaming his current personality for all his problems.
Ensemble Dark Horse: Takaya Sato, aka "2D-Kun," who a lot have made comparisons to being Keima from The World God Only Knows in another universe. Plus, in the original light novel series, there's an entire volume of side stories centered on him.
The slap, which sends Kouko flying in episode 16 is so ridiculous you will laugh. And the fact that the whole scene is so over-dramatic (a rolling shoe and all) doesn't help much.
Some of Ghost Banri's melodramatic, meant-to-be-taken-seriously dialogue will either make you groan or laugh at the Wangst.
Rescued from the Scrappy Heap: Despite her genuine kindness and empathy, Kouko didn't endear herself to many fans at the very beginning of the series. She used to stalk a guy who tried to get away from her (and she hasn't entirely grown out of stalker tendencies with her current boyfriend), bully her "love rival", is an extremely Clingy Jealous Girlshowing several signs of aggression and paranoia, and is in general rather spoiled, pushy, and controlling. Thankfully, she realizes her own faults, actively tries to improve herself, and goes through massive Character Development over the course of the show fairly early on, and proves to be the most layered Yuyuko Takemiya-written character this side of Ami Kawashima.
Values Dissonance: Kouko's father slaps her hard enough to send her to the ground and her boyfriend and friends are just standing there, not even trying to defend her (or rushing to help her). So apparently it's an acceptable way to chastise one's offspring. The father is also never criticized for his action on-screen or shown regretting it, and several scenes later he's shown again playing a part in goofy comedic scenes, implying he's been a "good" parent all along and there's no need to portray him as abusive. It is also shown later that he does truly care for Kouko.
Wangst: Banri's original personality seems to have been defined by it, in addition to being a crybaby.