In his past Natsume considered his ability more curse than gift -- to the point where upon finding out that a kind woman was a youkai was enough to make him verbally lash out and flee from her. He wanted very desperately to be "normal", accepted by his peers and family members, but he couldn't escape from who and what he was. As mentioned, this led to him being very withdrawn and putting on a happy face around other humans.
In the series, however, Natsume not only meets youkai who are kind, but people as well. Specifically the Fujiwaras, and a boy at his school, Tanuma. Though they know nothing about his abilities, the Fujiwaras are different in that they provide unconditional love for the first time in Natsume's life -- they support, shelter and protect him, and ask nothing in return except his happiness. This is at first very bewildering to Natsume, as he's used to viewing himself as a burden. Now, however, he's slowly coming around to the idea that he can be a part of a family, and he grows to be very protective of his new adopted guardians. Though they can see Nyanko-sensei (and willingly accept him as part of the family), they aren't aware of any other youkai activities. Because of this, Natsume goes out of his way to make sure they're sheltered from any nasty spirit-related side effects.
When it comes to Tanuma, who is "sensitive" to youkai (i.e., he can feel their presence and occasionally sees things out of the corner of his eye, but cannot see or communicate with them like Natsume can), there's a little more conflict. Natsume can no longer hide this part of himself from another human being, and he genuinely has no idea how to handle it, aside from trying to push Tanuma away. But again, to his surprise, Tanuma wants to offer his unconditional friendship, saying that it's his choice to be friends with Natsume, no matter what the consequences are. This is a hard concept for Natsume to take in, because it's a relationship that isn't dependent on his behavior, but simply on who he is.
Overall, when it comes to his human friends Natsume is significantly more guarded and protective, simply because he knows how fragile people are compared to spirits, and he'd rather put himself in harms way and be alone, than have anyone else in danger. Still, those few people who are stubborn enough to stay despite any weirdness are the ones who can slowly reach past his protective exterior and show him that he's worth being loved. When that happens, he becomes very protective and caring towards these people, unable to completely turn off that need to protect them, but learning how to balance it with simply being in relationships with others.
Revisions~
In his past Natsume considered his ability more curse than gift -- to the point where upon finding out that a kind woman was a youkai was enough to make him verbally lash out and flee from her. He wanted very desperately to be "normal", accepted by his peers and family members, but he couldn't escape from who and what he was. As mentioned, this led to him being very withdrawn and putting on a happy face around other humans.
In the series, however, Natsume not only meets youkai who are kind, but people as well. Specifically the Fujiwaras, and a boy at his school, Tanuma. Though they know nothing about his abilities, the Fujiwaras are different in that they provide unconditional love for the first time in Natsume's life -- they support, shelter and protect him, and ask nothing in return except his happiness. This is at first very bewildering to Natsume, as he's used to viewing himself as a burden. Now, however, he's slowly coming around to the idea that he can be a part of a family, and he grows to be very protective of his new adopted guardians. Though they can see Nyanko-sensei (and willingly accept him as part of the family), they aren't aware of any other youkai activities. Because of this, Natsume goes out of his way to make sure they're sheltered from any nasty spirit-related side effects.
When it comes to Tanuma, who is "sensitive" to youkai (i.e., he can feel their presence and occasionally sees things out of the corner of his eye, but cannot see or communicate with them like Natsume can), there's a little more conflict. Natsume can no longer hide this part of himself from another human being, and he genuinely has no idea how to handle it, aside from trying to push Tanuma away. But again, to his surprise, Tanuma wants to offer his unconditional friendship, saying that it's his choice to be friends with Natsume, no matter what the consequences are. This is a hard concept for Natsume to take in, because it's a relationship that isn't dependent on his behavior, but simply on who he is.
Overall, when it comes to his human friends Natsume is significantly more guarded and protective, simply because he knows how fragile people are compared to spirits, and he'd rather put himself in harms way and be alone, than have anyone else in danger. Still, those few people who are stubborn enough to stay despite any weirdness are the ones who can slowly reach past his protective exterior and show him that he's worth being loved. When that happens, he becomes very protective and caring towards these people, unable to completely turn off that need to protect them, but learning how to balance it with simply being in relationships with others.