In Nichiren Buddhism, the 10 realms include:

Hell-dwellers
Hungry ghosts
Animals
Fighting demons (asuras)
Humanity
Heavenly beings
Śrāvakas
Pratyekabuddhas
Bodhisattvas
Buddhas

Master Hsuan Hua’s One Thought–Ten Dharma Realms offers a very Chinese interpretation of the realm of ghosts, hungry or not.

Almost everyone has heard of ghosts, but not everyone believes in them. Even some Buddhists do not believe that there are ghosts.

You ask:
What are ghosts?
Ghosts are masses of yin energy.
Sometimes they appear
As a shadow with no form or
As a form with no shadow.

Perhaps you have seen a dark shadow, but when you looked closer it disappeared. Perhaps you have seen what looked like a person, but then that form vanished in the blink of an eye. These phenomena are not easy to understand.

Ghosts are another realm in the ten Dharma Realms. There are as many different kinds of ghosts as there are grains of sand in the Ganges River. Some ghosts are affluent and powerful and reign as kings over the ghost realms. However, some are poverty-stricken and devoid of authority–it is often the poor ghosts who bother people and go about causing trouble. If you want to know how many kinds of ghosts there are, work hard on your cultivation, open the five eyes, and develop the six spiritual powers, and then you’ll know.

As for people who say there are no ghosts, I tell them that if there are no ghosts, then there are also no Buddhas, people, or animals, because animals are transformed from ghosts, and so are people, asuras, and so forth. The same applies to devas, Arhats, Solitary Sages, Bodhisattvas, and Buddhas.

Why is this?

The ten Dharma Realms are not beyond a single thought. A single thought creates the ten Dharma Realms.

One Thought–Ten Dharma Realms, p70

As a bonus, I offer a Chart of the Heavens. This chart comes from a Chart of Samsara published in Buddhism: A Brief Introduction. Appendix 1 Page 127-131

Yesterday’s post about Chinese Master Hsuan Hua’s One Thought–Ten Dharma Realm concluded with a mention of the Age of the Dharma’s Ending. One of the joys of reading this book for me was the footnotes. On the bottom of page 56 we learn:

There are Three Ages of Dharma in Buddhism: Right Dharma, Semblance Dharma, and Dharma’s Ending

1. The Age of the Right Dharma was the first 1,000 years after the Buddha’s passing when his disciples were diligent in their practice and awakened to the Dharma.
2. The Age of the Semblance Dharma was the second period of time lasting 1,000 years. People are devoted to the external signs of the Dharma but not many have direct knowledge of the Dharma.
3. The Age of the Dharma’s Ending is the third period of 10,000 years, when the Dharma is about to disappear and people like to fight and compete rather than cultivate. We are currently in this age.

Although the Three Ages are described in time periods, another way of understanding them is in the present moment. A thought of fighting is the Age of the Dharma’s Ending, a thought of true practice is the Age of the Right Dharma. Similar to the ten Dharma Realms, the Three Ages are also not beyond a single thought in the mind.

Another example is the footnotes on page 49 for the five precepts, the ten good deeds and outflows.

The five precepts consist of 1) not killing. 2) not stealing, 3) not committing sexual misconduct, 4) not lying, and 5) not taking intoxicants. Buddhist practitioners can request to receive these precepts formally as a vow that they then uphold. These precepts are the foundation for spiritual practice.

The ten good deeds are 1) no killing, 2) no stealing, 3) no sexual misconduct, 4) no lying, 5) no divisive speech, 6) no harsh speech, 7) no frivolous speech, 8) no greed, 9) no hatred, and 10) no delusion.

Outflow (Skt. asrava, Ch. you lou 有漏) literally means a “leak” or “flowing out” that an awakened being puts an end to. There are usually three outflows: 1) outflow of sensuality, 2) outflow of existence, and 3) outflow of ignorance. Doing good deeds with outflows is like trying to put water in a leaky bucket. No matter how much water we put into it, the bucket never gets full. For example, if we practice giving with an expectation to be rewarded in the future, then our practice of giving has outflows. The ideal is to give without any attachments or expectations, which ultimately allows us to become free of the conditioned realm.

The discussion of Asuras on page 57 says:

Asuras may be born in the heavens, in the human realm, or in the realms of animals and hungry ghosts.

Dragged by the force of their karma,
they become deluded and confused,
create more karma, undergo the results of their actions,
and then are born again due to the force of their karma.

As cultivators, we must not be contentious, aggressive, or have a violent temper. Then we will be free of the asura realm.

In the footnote we get this explanation of Karma:

Karma is defined as intentional action of body, speech, and mind. Therefore, the force of karma is simply the habitual patterns that push us along into our next moment of existence. If the scope of time is expanded, then the power of karma is in our deep-seated habits that push us on from life to life. However, despite our conditioning, at every moment we have the opportunity to choose what karmic action to take. The Buddha’s teachings give us the tools to take that opportunity rather than just be slaves to our habits.

It is also important to note that karma is not only negative, but can be classified as good, bad, mixed, and neither good nor bad. Good karma leads to a good rebirth, while bad karma leads to a bad rebirth. Mixed karma, a combination of good and bad actions leads to good and bad results. Finally, karma that is neither good nor bad comes from cultivating precepts, meditative stillness, and wisdom. This final type of karma has no outflows and leads to awakening.

Next: Do You Believe in Ghosts?