One reason could be that Naruto has been through so much himself and he might think rookies are naive. He's seen the harshness of the ninja world and doesn't want to coddle them. For example, he had to grow up without his parents and faced many life - threatening situations early on.
It creates conflict. The rookies might be initially discouraged or resentful of Naruto's coldness. This can lead to them trying harder to prove themselves, which drives the plot forward as they strive to gain Naruto's respect.
I'm not sure specifically as I haven't read that particular fanfic. But it might be about Naruto getting angry at the rookie ninjas for some reason, perhaps they made a mistake during a mission or did something that goes against his values.
Obviously Naruto is one of the main characters since the title mentions him. And the rookies are also main characters, though we don't know exactly which rookies without reading it. It could be the ones from his own generation like Sakura, Sasuke, etc., or it could be new rookies that Naruto is mentoring.
Perhaps he reveals his dreams for the future of the Hidden Leaf Village that are more personal and not part of his official Hokage - related goals. For example, he might talk about his hopes for how the different ninja clans interact and co - exist in a more harmonious way, something that he has been thinking about but hasn't shared with the group yet.
'Cicada and Robin' was a classical Chinese text that described a conversation between a cicada and a Robin. The cicada said to the bird,"Although you can imitate human speech, what you say is not what you want to say, unlike my own voice that can express my feelings." The red-robed bird felt ashamed and stopped imitating human speech. This story implied that people should have their own independent thoughts and expressions.
They would probably be shocked. Since Naruto is such an important figure to them, any big secret would likely cause a stir. For example, if it's about his Nine - Tails secret, they might be initially stunned as they realize how much he has been carrying alone.
In some fanfics, Naruto might be depicted as cold - hearted, but it goes against his canonical character. The original Naruto is known for his warm - heartedness, determination, and his ability to see the good in people. Fanfic authors may take creative liberties for various reasons like exploring different storylines or character arcs, but it's not a common or true - to - the - source representation of Naruto.
Well, in fanfic, Naruto could be a cold person if the writer decides to put him in a very different context, like after facing extreme betrayals or in a dark alternate universe. But this goes against his core traits in the main story. He's typically the one who tries to reach out and bring warmth, but fanfic can change that perception for the sake of creativity.
One characteristic could be a cold - hearted or aloof main character. In Naruto yaoi fanfic, this character might be distant at first, creating a sense of mystery. For example, a character like Sasuke could be portrayed as very cold towards others, especially in a yaoi relationship context.