Hanekawa tells Araragi how Karen caught the bee oddity. She met with Kaiki, whom Hanekawa tracked down, to confront him about selling charms to middle schoolers, and to punch and kick him. However, after demoralizing her with his motives and worldview, he touches her on the forehead, delivering the bee. Back in the present, Hanekawa urges him to solve the dilemma that night, as he must return to his studies tomorrow. Wiping down Karen’s sweat, Araragi realizes (and it’s confirmed by Shinobu) he can cure Karen by transferring the bee poison to himself – via a kiss.
In the series’ usual stage play-like format, this episode presents the opposing positions of Karen Araragi and the con man Kaiki in no uncertain terms. Karen is a girl of strong principles and, to hear her tell it, the “blood of justice” courses through her veins, urging her to oppose, confront, and punish evil like Kaiki, who takes a Gordon Gekko-like “Greed is Good” stance. To him, filling his bank account with the bounty of evil deeds is no different from Karen filling her heart with good deeds. They are two sides of the same coin…and his worldview isn’t too far removed from that of wild nature – which exploits weakness without compassion and puts the self above all else.
Karen tells him there’s something inhuman about him, and she’s right; humans have evolved to balance their selfish primal urges with the good of humanity as a whole, which benefits both parties. Society and civilization could not survive if everyone was like Kaiki. You need some Karens. You also need Hanekawas and Koyomis; who see both sides and can mediate, since nothing Karen or Kaiki say to one another will ever get through – their philosophies are too opposed. Kaiki sees her morality as primitive, but it’s he who is acting like the heartless animal. But the same blood in Karen is also in Koyomi, which is why he’ll put his life on the line to save his little sister.