A high-level secret Gentle Fist technique taught only to the main branch of the Hyūga clan. The user changes the shape of chakra released from both hands into large lion-shaped shrouds. Doing so greatly increases range and destructive power. The lion heads drain the chakra network of those they touch. It is an extremely difficult ability to learn, as the slightest mistake in chakra control will lead to failure, meaning it is a feat requiring the Byakugan.
Interestingly, the lions make the technique closely resemble Dogs-Lions Japanese Guard. This is probably a reference to the use of the technique in the fight against Pain to defend Naruto, as well as dogs/lions rush away the evil souls of Japanese temples.
In Naruto Shippūden: Ultimate Ninja Storm 2, to execute the Gentle Step Twin Lion Fists, Hinata hits her opponent multiple times with her palms, pushing them back. Then she forms the lion heads and slams them into her opponent, where they explode and send the opponent flying back.