Shingon is a form of Esoteric Japanese Buddhism that was founded by the Buddhist monk Kukai in the 9th century. It is also known as Shingon Mikkyo, which means "True Word Esotericism." Shingon is considered to be one of the most influential and popular forms of Buddhism in Japan.

One of the reasons for Shingon's popularity in Japan is its unique blend of Buddhist teachings and traditional Japanese culture. Shingon incorporates elements of Shintoism, Taoism, and Confucianism, making it more relatable and accessible to the Japanese people. This integration of different beliefs and practices has helped Shingon to become deeply ingrained in Japanese society.

Another factor contributing to Shingon's popularity is its emphasis on ritual and ceremony. Shingon practitioners engage in various rituals and ceremonies, such as chanting mantras, performing mudras (hand gestures), and using mandalas (sacred diagrams) to aid in their spiritual practice. These rituals and ceremonies are not only visually captivating but also provide a sense of community and belonging for Shingon followers.

Shingon's teachings also focus on the attainment of enlightenment in this lifetime, which is a concept that resonates with many Japanese people. The goal of Shingon is to achieve Buddhahood through the practice of meditation, visualization, and other esoteric techniques. This emphasis on self-improvement and personal growth has made Shingon an attractive form of Buddhism for many Japanese individuals.

In addition to its spiritual teachings, Shingon also has a strong cultural and historical significance in Japan. Many of its temples and shrines are designated as UNESCO World Heritage sites, attracting both tourists and locals alike. The annual Shingon festival, known as Goma, is also a popular event that draws thousands of visitors to witness the elaborate fire rituals and ceremonies.

In conclusion, Shingon is undoubtedly a popular form of Buddhism in Japan. Its unique blend of teachings, rituals, and cultural significance has made it deeply rooted in Japanese society. Its popularity continues to grow, and it is estimated that there are over 12 million Shingon followers in Japan today.