While Koyomi is in Sengoku's place, she informs him that his sisters are acting strange and they are somehow investing an spell, therefore Koyomi decides to talk with his sisters.
Part 2 of 7. Nadeko tells Koyomi that his young sisters Karen and Tsukihi have been investigating problems with a shady "incantation". He warns his sisters not to get deeply involved, because he already knows what kind of thing the incantation is.