Kōketsu

Kōketsu (膏血, Rewards of Sweat and Blood) is the katana possessed by Chiyome Mochizuki, and is an ancestral item inherited from a line of warriors with the same bloodline as the first Chiyome Mochizuki. However, due to her status as her supposed reincarnation, Chiyome was granted this blade despite not being a blood relative of the woman. It is regarded as a rather unique katana despite its simplicity.