Nisemonogatari is a story about fake things (fake means unreal, immature, and hypocritical). Koyomi and his girlfriend Senjougahara are fake things; Koyomi's two sisters Karen and Tsukihi are fake things; the fraudster Kaiki is also a fake thing. In contrast, Hanekawa is a very powerful real thing. The weirdness in Nisemonogatari is related to Koyomi's sister, which triggers a series of events.