It could be the result of some kind of special training. Maybe he met a hermit who taught him a unique technique to perceive chakra in a visible way. For example, this hermit might have had him meditate in a special chakra - rich area and gradually opened his eyes to the world of visible chakra.
Well, Naruto's ability to see chakra can give him a huge advantage in combat. He can easily detect an opponent's chakra flow and predict their moves. For example, if an enemy is gathering a large amount of chakra in their hands for a powerful attack, Naruto can see it and dodge or counter - attack before the attack is launched. This allows him to be more proactive in battles instead of just reacting to his opponent's visible actions.
One interesting concept could be a character unlocking the hidden potential of the chakra gates in a unique way. For example, they might discover a new sequence of opening the gates that gives them powers beyond what was thought possible in the original Naruto lore.
Fanfiction can expand on chakra gates training by introducing new training regimens. For example, a fanfic might have a character train in a special chakra - rich environment that accelerates their understanding of the chakra gates.
Naruto's dense chakra could make his friends either jealous or in awe. If he can do things with his chakra that others can't, some might envy his power. But his true friends like Sasuke and Sakura would be in awe and see it as a way to strengthen their team. For example, Sasuke might see Naruto's dense chakra as a new challenge to keep up with, which could improve their friendly rivalry.
One consequence could be that he becomes extremely powerful. His physical abilities like strength, speed, and endurance are enhanced. He can also use more powerful jutsus with the extra chakra boost from the Kyuubi.
One interesting way is when Naruto absorbs chakra through his shadow clones. In some fanfictions, the clones can be used not just to gather information or attack, but also to absorb the chakra of the opponents they interact with. Then, they transfer this absorbed chakra back to Naruto, making him more powerful.
Perhaps there is an ancient artifact or a powerful curse that causes Naruto to absorb all chakra. In the fanfiction world, it's common to introduce such unique elements. For example, he might find a magical scroll that, when opened, starts sucking in all the chakra in the vicinity and then channels it into Naruto. Or it could be a curse placed on him by an enemy, but instead of harming him, it gives him this strange power to absorb all chakra.
The consequence might also be a shift in the balance of power in the Naruto universe. With all that chakra, Naruto could potentially change the political situation. He could end wars single - handedly or force the different ninja villages to re - evaluate their strategies. Moreover, his own physical and mental state might be affected. There could be a struggle within him to keep his identity intact while dealing with such an overwhelming power source.
He could share it with Hinata. Given their relationship, Naruto might transfer some of his chakra to Hinata to protect her during a dangerous situation. This would also strengthen their bond further in the fanfiction.