Introduction:
Japanese writing system consists of three scripts: hiragana, katakana, and kanji. Kanji, which are adopted Chinese characters, form the basis of the Japanese writing system. Therefore, it can be said that Japanese borrowed their written script from China.

Explanation:
The adoption of the Chinese script by the Japanese can be traced back to the 5th century when Japan was heavily influenced by Chinese civilization. During this time, Japan sent numerous missions to China to learn about Chinese culture, including their writing system.

Historical Background:
1. Introduction of Chinese Characters: The earliest known contact between China and Japan dates back to the 1st century CE. However, it was not until the 5th century CE that Chinese characters were introduced to Japan.
2. Buddhism: The spread of Buddhism from China to Japan during the 6th century further strengthened the cultural ties between the two countries. Buddhist scriptures were written in classical Chinese, which led to the adoption of Chinese characters in Japan.
3. Development of the Japanese Writing System: Over time, the Japanese adapted the Chinese characters to suit their own language and pronunciation. This led to the development of two additional scripts: hiragana and katakana. Hiragana is used for native Japanese words and grammatical elements, while katakana is used for foreign loanwords and emphasis.

Significance of Chinese Characters in Japanese Writing:
1. Kanji: Kanji, which are adopted Chinese characters, are an integral part of the Japanese writing system. They are used to represent nouns, verbs, adjectives, and other important parts of speech.
2. Complexity: Kanji can be complex and have multiple readings, making them a challenge to learn. However, they also provide a depth of meaning and convey nuances that would be difficult to express using only phonetic scripts like hiragana and katakana.
3. Cultural Significance: The adoption of Chinese characters in Japan not only influenced the language but also had a profound impact on various aspects of Japanese culture, including literature, calligraphy, and art.

Conclusion:
In conclusion, the Japanese borrowed their written script from China. The adoption of Chinese characters, known as kanji, formed the basis of the Japanese writing system. Over time, the Japanese developed their own scripts, hiragana and katakana, but the influence of Chinese characters remains significant in Japanese language and culture.