The Sexy Technique is simply a Transformation Technique used to transform the user into a beautiful, nude woman in a very seductive posture with mists of smoke covering part of the body, or a woman in a bathing suit. Naruto uses it to distract or win over men, sometimes leading to an exaggerated nosebleed by the victim, though some men have been able to resist it.
Since his return in Part II, Naruto has bragged that he has a new-and-improved upgrade for this technique, but he was punched by Sakura into the distance. In the omake chapter in the second Naruto Fanbook, Naruto performs the upgrade in front of Jiraiya taking place during the time-skip.

Users
Naruto Uzumaki
Konohamaru Sarutobi
Moegi
Udon

Classification
Ninjutsu

Rank
E-rank

Class
Supplementary