Mann and the charity Heal the World are both in litigation with the estate. The estate has obtained a court order prohibiting the foundation from using Michael Jackson's name, but Katherine and other family members still support it.
"I think it's greed, fundamentally," Mann told ABC News. "I think that the notion … that Mrs. Jackson is not able to use her son's name or the Heal the World foundation, is stopped by the courts from using Michael's name, is utterly ridiculous to me. I don't understand whose agenda this services, outside of maybe a group of lawyers."
In a statement to "Good Morning America," Jackson's estate said they believe Mann is making these allegations for his own financial gain.
"The current Heal the World Foundation has no relation to Michael Jackson's charity that touched so many lives before becoming inactive several years before Michael's death...The Estate does not believe Michael's children should be used to exploit a foundation that a federal judge found was not associated with Michael Jackson."
The children may remain committed to fulfilling their father's legacy, but they're also focused on living their lives as normally as they can. "This is the first time they ever had regular schooling. They always had homeschooling (before)," Jackson said of Paris and Prince. Blanket is still homeschooled.
"They seem to be adjusting to it well. They love it. I don't even have to make them get up, they just get up and get ready for school."
Prince Michael's favorite subjects? "Gym and lunch," he said jokingly. He also plays basketball, and recently won a season-ending game. "He's a beast!" Paris said of her brother's skills on the basketball court.