You should watch "Kizumonogatari Part 1: Tekketsu" first, as it is the beginning of the Kizumonogatari trilogy. This film introduces the backstory of Araragi Koyomi and his encounter with the vampire Kiss-shot Acerola-orion Heart-under-blade, setting the stage for the subsequent parts, "Kizumonogatari Part 2: Nekketsu" and "Kizumonogatari Part 3: Reiketsu." Watching them in order enhances the understanding of the characters and plot development.

"Kizumonogatari Part 1: Tekketsu" has a runtime of approximately 58 minutes. This anime film is the first installment in the "Kizumonogatari" trilogy, which is part of the larger "Monogatari" series created by Nisio Isin. It explores the backstory of the protagonist, Koyomi Araragi, and his encounter with the vampire Kiss-Shot Acerola-Orion Heart-Under-Blade. The film is known for its unique animation style and intricate storytelling.

"Kizumonogatari" consists of three parts: "Kizumonogatari Part 1: Tekketsu," "Kizumonogatari Part 2: Nekketsu," and "Kizumonogatari Part 3: Reiketsu." These films serve as a prequel to the "Monogatari" series, focusing on the character Araragi Koyomi and his encounters with various oddities. The trilogy explores the backstory of Araragi's transformation and his relationship with the vampire Kiss-Shot Acerola-Orion Heart-Under-Blade.

"Kizumonogatari Part 1: Tekketsu" is the first film in the "Kizumonogatari" trilogy, which serves as a prequel to the "Monogatari" series. Released in 2016, it follows the protagonist, Araragi Koyomi, as he encounters the vampire Kiss-Shot Acerola-Orion Heart-Under-Blade. The story delves into Araragi's transformation after a fateful encounter and explores themes of identity, sacrifice, and the supernatural. The film is notable for its unique animation style and deep character development.