Who is Peter in "diary of …

Peter van Daan, a shy boy of sixteen, was unlike other boys. A thoughtful and sensible observer, he was different from his loud and brash parents. As he had no friends and could not reach out to his parents, he appeared sullen and difficult. Initially, Anne considered him to be hypochondriac and lazy. However, he turned out to be peace-loving, tolerant and extremely easygoing.
His contemplative years were spent in the annex. He was much more closed than Anne was and took time to open up as Anne says is characteristic of uncommunicative types. He began confiding in Anne and made a determined effort to express his innermost self. Their relationship was not romantic, but forged out of a necessity to find a kindred spirit in such trying times. In Anne, Peter found the tenderness and comfort that he had been searching for; it made him offer his friendship for the first time to someone.