For Westerners, the “scary” time of year (besides tax season) is Halloween, but Japan has a similar tradition, called Obon (お盆) season which arose from a totally different set of circumstances, yet is an interesting example of convergent (and yet divergent) cultural traditions. Obon season in Japan varies by region: in the eastern “Kantō” part of Japan it’s around July 15th, while in the western “Kansai” part of Japan it is around August 15th. The reasons for this are due to certain political/historical reasons we won’t get into here. Despite the differences in timing, the traditions are still basically the same.
Obon, which literally means “serving tray”, is loosely derived from a Buddhist sutra called the Ullambana Sutra (盂蘭盆経; urabon-kyō in Japanese) wherein one of Shakyamuni Buddha’s chief disciples, named Maudgalyayana (or Mogallana), experiences a vision during a deep state of meditation. In this vision, he sees his mother trapped in one of the many Hell realms.1 His mother, while doting on lil’ Maudgalyayana, tended to bad-mouth others and did a lot of negative things all for the sake of her son.2
Maudgalyayana felt terrible about this, and resolved to help get his mother out of Hell, so he consulted with Shakyamuni Buddha, who said that if Maudgalyayana made offerings to the rest of the monastic community and dedicated the good merit to his mother, his mother would be liberated and could move onto a better rebirth. As the story goes, Maudgalyayana carried out the Buddha’s advice (hence the “serving tray” referring to Maudgalyayana’s offerings to the other monks). Having accomplished this, he later had a vision of his mother being liberated from Hell as a result.
Thus, in China and Japan this story has served as an inspiration for late-summer festivities that revere the ghosts of ancestors, offering gratitude to them, and so on. It’s an interesting example of how Buddhist teachings intermingle with local beliefs to create a cultural tradition (much the same way that Halloween is a mix of pre-Christian Celtic + early-medieval Christian traditions). It’s also why ghost stories are popular around this time. The famous book Kaidan (older spelling Kwaidan) by Greco-Irish author Lafcadio Hearn is a rare English-language window into some of these classics ghost-stories. I’ll post a few such stories later this week.
In practical terms, Obon has a lot of parallels with the Mexican Day of the Dead festivities. Offerings are made to one’s ancestors in the family Buddhist altar (butsudan, 仏壇), and families will also visit ancestral graves to clean them up and make further offerings there (ohaka-mairi, お墓参り). People often take time off around this time, or companies have work holidays (obon-yasumi お盆休み) to allow people to return to their hometowns, relax and get in touch with family again.
The most well-known custom of Obon is the communal dance or bon-odori (盆踊り) which you’ll often find in overseas Japanese communities as well. I’ll post some videos or something soon of the Bonodori dances in my wife’s neighborhood, which we often visit around this time. My daughter, who’s now a teenager and knows a lot of the neighbors, helps volunteer at the local bonodori every year.
Anyhow, while Obon season is very much a Japanese tradition, it also has fascinating roots from both China and Buddhist India as well.
P.S. The July vs. August celebration of Obon happens not just between east and west, but can vary by region. Northern Japan also celebrates in August while the Tokyo area celebrates in July, and so on.
1 Buddhism, borrowing from earlier Indian cosmology, describes many hell realms and many heavenly realms. All of these are seen as temporary destinations on the even longer cycle of rebirth. For Buddhism, the larger goal is liberation from the near-infinite cycle of rebirth (Samsara, or “aimless wandering”) more than seeking out the “good” realms over the bad ones.
2 I think this often gets overlooked, but the Ullambana Sutra is a poignant reminder that not everything done for the sake of one’s kids is the right thing to do. Parents need to uphold good moral conduct in addition to good parenting. They’re not necessarily exclusive either. In simpler terms: don’t be a dick.
Gleanings in Buddha-Fields 
