Kyuuingan

The Kyuuingan (吸引眼, Literally meaning: Suction Eye) is the doujutsu kekkei genkai from the Mayonaka Clan.

Overview
When the Kyuuingan, the user's eyes turn to a light blue color with white pupils. It is available to the user from birth. Unlike some other doujutsu, a transplanted Kyuuingan can be activated and deactivated upon will, and with enough training, a non-Mayonaka can master it and use it without wasting their chakra.

Abilities
The Kyuuingan grants the user the power to absorb chakra from any person or object they come in direct contact with, and then, utilize it as if it were their own. By absorbing chakra from a nature that the user doesn't possess, they also become able to use said nature. Hard training may also enhance the user's vision, giving them more insight.

The speed in which the user can suck chakra out of something depends on their training, and for that reason, members of the Mayonaka clan train by sealing chakra into objects and absorbing it to enhance their power. A Kyuuingan user can also detect if a genjutsu is being put over someone by feeling their disturbed chakra as they absorb it. Prolonged use of the Kyuuingan can damage its user's chakra pathway system, sometimes rendering them unable of performing ninjutsu techniques and absorbing chakra.

Being able to suck chakra only from things that are touched directly is considered to be the on and deadly flaw of the Kyuuingan. Acknowledging this, Natsu Mayonaka put himself through arduous training to try overcoming that flaw; he succeeded to a certain point: by part I, he can suck chakra out of things that are 60 centimeters away from him, which by part II grows to 135 centimeters, and by adulthood, remains at 5 meters. Yuu Mayonaka was shown to achieve the same: in the end of part I, she can absorb chakra from anything that is 5 centimeters away from her; during part II, that distance grows to 90 centimeters; during her adulthood, she is shown to be able to absorb chakra from any person or object that is 4 meters away from her. As they were considered to be some of the most experienced Kyuuingan users, it's implied that Hideaki and Hibiki Mayonaka could also do this, but to unknown extents, just like Yukari Mayonaka.

Most Kyuuingan users are also highly experienced in taijutsu, as they need to connect direct physical attacks to absorb chakra more easily and faster.

Trivia

 * The wielder sometimes uses certain hand seals before activating the Kyuuingan.