"Nisemonogatari" is the second installment in the Monogatari series, written by Nisio Isin. It follows the protagonist, Koyomi Araragi, as he navigates complex relationships and supernatural events involving various characters, particularly his sisters, Karen and Tsukihi Araragi. The story delves into themes of identity and deception, as the title "Nisemonogatari" translates to "Fake Story." Throughout the series, Koyomi encounters different oddities and challenges, exploring the nature of truth and the impact of lies on personal connections.