Please note that this is the Narutopedia's article on the genjutsu used by Itachi Uchiha. If you are looking for the article on the anime-only kinjutsu used by Kagerō then you should head to Antlion Ninja Arts: Ephemeral. For other uses, see Utakata (disambiguation).
Itachi seemingly activates this technique by simply pointing at his target. When the technique was used on Naruto Uzumaki, crows flocked from Itachi and turned into shuriken that bombarded him, and then attempted to put him to sleep. When he resisted the sleep command, Naruto then experienced the sensation of his body parts turning into his closest friends who then tortured him psychologically.
This genjutsu is never named in the anime, manga, or manga databooks. It is instead given a name in Naruto Shippūden: Gekitō Ninja Taisen! EX. These video game variations only consist of the damage caused by the crow-turned-shuriken.
In Naruto Shippūden: Ultimate Ninja 4, this technique is called "Genjutsu: Bubbles". This may be an allusion to the impermanence of bubbles and "Ephemeral" literally meaning something akin to "for a moment" or a short while.