Nisemonogatari

Synopsis

Back at his house, Koyomi meets Tsubasa who is helping Tsukihi tend to a feverish Karen. It turns out that Tsubasa has been helping Karen with her "mission." Koyomi gets angry at Karen for doing something dangerous and getting assistance from Tsubasa without his knowledge. Tsubasa and Koyomi then go to his room to talk about what happened. After talking with Tsubasa, Koyomi goes to take a bath. While taking his bath, Shinobu emerges from his shadow. Koyomi is shocked to find that Shinobu is actually very talkative. Shinobu then tells Koyomi that Karen was inflicted by a lethal, supernatural bee. The bee sting causes an extremely high fever and makes the inflicted person feel as if they are on fire. (Source: Wikipedia)