His opponent sliced him in a spot he'd never been cut before, which, when one considers the number of injuries he'd acquired over his lifetime, was a bit of a surprising experience. Instead of the usual pain, there was a brief burning sensation, a loud pop, and a brilliant flash of light. When the light vanished, his center of gravity was off. Not only that, but his opponents were looking at him in shocked surprise. The surprise rapidly vanished, and one of his opponents moved in for another attack.
As he blocked his opponent's blows, he felt his upper arms repeatedly brush against something on his chest. Confused, he looked down.
"...the fuck?" he said when he found himself looking down at a pair of breasts.
"Well, that explains everything." Kakashi, who had been silent to this moment, said while he was occupied with the strange lumps that had magically appeared on his chest.
"What explains what?" he asked, somewhat confused.
"Prolonged use of Gender Switching seals has been proven to cause mental instability." Kakashi explained.
"Gender wha...?" he said as his other opponent ceased trying to attack him and started looking rather thoughtful.
"If that is the case." Maito Gai said eventually. "Then perhaps I should have mine removed as well."