Koto Taikan (古銘古刀大鑑) and Shinto–Shinshinto Taikan (新々刀大鑑) by Iimura Kōkan are monumental reference works dedicated to the study and identification of Japanese swords. These large-format volumes present extensive oshigata and documentation of important blades from the Koto, Shinto, and Shinshinto periods, offering detailed examples of signatures, workmanship, and stylistic characteristics of major smiths and schools. Compiled with the serious student and collector in mind, the Taikan volumes serve as essential research tools for kantei and comparative study, preserving valuable records of historically significant blades and providing insight into the development of Japanese sword craftsmanship across the centuries.