The Nirmanakaya Buddha comes into this world with the vow that he will save all sentient beings. Not by karma, but by vow, he appears in this world, practices the Bodhisattva’s way, attains enlightenment as Buddha did, and saves all human beings. So, he is called an incarnated body. He changes his form in various ways, sometimes to a bodhisattva, sometimes to a buddha. He takes on various forms to help people, so in the widest sense of the word, everything is Nirmanakaya Buddha. But in the narrow sense, those who appear in this world by vow instead of by karma are called Nirmanakaya Buddhas.
Jizo Bosatsu and Kanzeon Bosatsu statues
—cuke.com/ig for links to the source of the photo. Excerpt from Shunryu Suzuki lecture 68-10-00-B as found on shunryusuzuki.com, edited by PF. Go to instagram.com/cuke_archives for the Instagram version.