Natsume is an orphan. When he was younger, his parents died, and he was constantly sent to live with relatives. Because of his ability to see spirits, Natsume would scare his relatives because they didn't understand what he was doing. Eventually, Natsume lived with the Fujiwaras, an old couple from his father's side. He loves them, and does not want to cause them trouble, so he keeps quiet about his problem. Though he is rather slender, Natsume is incredibly strong when it comes to Youkai, having enough strength to knock spirits (mainly Nyanko-sensei) out with one blow (backed up with his spiritual powers).
Source from Wikipeida
|quiet , slender, strong|