A Japanese Buddhism, Shingon-shu was founded by Kukai (called also St. Kõbõ. Kooboo Daishi, the great teacher, 776-835), before this Heian period (794-1185), Buddhism were Chinese style and Indian style- called Nara period of Buddhism (710-784).
One can reach Buddha (Jobutsu) if one does three things:

1. IN: Hand posture (Tight your hands in special Shingon IN-position)

2. Mantra: Your mouth repeat Shingon Mantra.

3. Mind: Be a mind of Buddha and practice his teaching.

Shin means Truth. Gon means words, mantra or what you say.
Shingon-shu has 14 million diciples and 12000 temples in Japan.
Daishoji / Daikakuji sect have more than 2000 temples.