Incomplete/unclear question. However, here's what is known about Mr. Kraler in the story.
Explanation:
He was very helpful in keeping the Franks safe. Been a business associate of Mr. Frank, he was handed over the business by Mr. Frank and Mr. Van Daan. Kraler was was helpful in preparing the secret hide out used by the Franks when their lives were in danger, we're told he obtained supplies for them. Yes, Mr. Kraler was indeed good towards the Franks all through their difficulties.
