- Name: Imperfect Tsukuyomi (不全月読, Fuzen Tsukuyomi; Literally meaning "Imperfect Moon Reader")
- Type: Kekkei Genkai, No rank, Supplementary, 20m radius centered on user
- User: Mori Ketsueki
When Mori Ketsueki used the Blood Release: Forbidden Blood Vampire on Itachi Uchiha and gained the Sharingan, Itachi transferred a small amount of his mastery as well. Due to the nature of the Kinjutsu and the chakra requirements of the Mangekyo Sharingan, Mori generally uses a variation of one of Itachi's most feared techniques.
Unlike the standard Tsukuyomi, where Itachi controls the time and space of the dream world, Mori actually creates a localized time warp. Anything that enters within 20 meters of Mori is subject to this temporal distortion. To Mori, it appears as if everyone else is moving in slow motion. This allows him to freely attack his opponents for a short duration. Because of the intense chakra use, Mori usually with only use this jutsu in desperation, activating the third or fourth chakra gate and compressing about 10-20 minutes into 3 seconds.
Like the standard Tsukuyomi, a large red moon hangs overhead, painting the sky blood red. Everything else is pitch black while individuals appear as greyscale negatives.
Despite its name, the Imperfect Tsukuyomi is not necessarily less powerful than Itachi's genjutsu. Itachi's distortion of time and space only alter's the victim's perception of time and space, while the Mori's actually distorts time. The term Imperfect instead comes from the jutsu being only half of a powerful time-space jutsu such as the Flying Thunder God Technique and Madara's Space-Time jutsu.