Many small kingdoms came to together to united around the capital Nara; around the 4th and 8th centuries. Around this period, agriculture improved dramatically and adopted new ideas from China. One of the ideas adopted from China was, Pictographic writing, called Kanji and which, later came Hiragana and Katakana. They also adopted architecture, Confuciusm and Buddhism.
Even though Buddhism became Japan’s state religion in 594.