Episode 10 of B Gata H Kei was uncharacteristically fast-paced, given the tone the last few episodes have set. It hearkened back to the frantic pacing of the first episode, in more ways than one.
In particular, the final scene of the episode brought with it the culmination of a subtle secondary idea the show has been building up to in Kanejou. From her first appearance at the school festival, and more formally on her introduction as a main character, Kanejou has unmistakably branded as the closest the show is likely to come to a villain. At every turn she is conniving, hoping to control the school for no reason but the fun of it, and making herself the biggest inconvenience to Yamada in particular possible - fitting for a self-centered sex comedy rival. And an incestuous crush, to boot.
But most of those things describe Yamada - her ostensible goal of sex with 100 men is nothing if not a (misguided) quest for social stature; she is manipulative and coarse in pursuit of her goals; and she hates and inconveniences Kanejou at least as much as vice versa. So why is one such a likable protagonist, and the other such a loathsome rival?
Perspective - Yamada is a narrated character. Her “erogami” follows along with the audience, noting all of her mistakes and insecurities - things which make her human and relatable. Kosuda, as well, grew a dimension and became a tangible character with actual depth around when his own erogami was introduced. B Gata reveals its characters’ humanity in spite of the front they present to the world through these little-explained, semi-diegetic fourth-wall-sitters. And in episode 10, both Kanejou and Miyano’s erogami are introduced.
Miyano’s erogami appears during an emotionally-tense dialogue with Kosuda in which she’s barely able to contain herself while advising the boy she loves about his love of another girl. It provides some light comedic relief as a transition into the following scene, but also serves to signal to the viewer that she is a real character - her emotions here are as real as any in the show, and she is not simply a clumsy set piece in Yamada and Kosuda’s romance.
Kanejou’s erogami is more devious in its appearance - after Kanejou “kidnaps” Kosuda and begins her efforts to seduce him, she finds herself at a loss for what to do. Her erogami appears, and she instantly becomes a nervous wreck reminiscent of the Yamada of the first few episodes - not thinking straight, she begins stripping in front of Kosuda, at the same time exhibiting more of a will to attack than to seduce in her body language. For a moment she is the spitting image of Yamada, shoving Kosuda in a storage closet and pulling her shirt open defiantly.
Suddenly our awareness of her unsavory sexual motives take an immediate backseat to her mental breakdown, and her despicable antics give way to a light, comedic tone. Most important, within the span of a few seconds, she becomes human. When we see behind the veneer of her outer persona - in a more honest sense than our discovery of her brother complex - she is irrevocably humanized. She is, at worst, only as bad as the girl we have been rooting for since the very first episode.