Why were the earliest Japanese texts written in Chinese?

The earliest Japanese texts were written in Chinese primarily because the Japanese had not yet developed a system to transcribe the sounds and grammatical structures of their own language when they first encountered Chinese civilization between the 1st and 4th centuries CE.12

Because the Japanese language is fundamentally different from Chinese—being an inflected language rather than a monosyllabic, isolating one—Chinese characters were not naturally suited to represent Japanese. To bridge this gap, Japanese scribes adopted Chinese characters using several methods:23

• Phonetic usage: Characters were used for their sound values rather than their meanings to approximate Japanese pronunciation.1
• Kun writing: Characters were used to represent Japanese words that shared a similar meaning.3
• Mixed systems: Early works, such as the Kojiki, often employed a complex combination of these methods.1

Additionally, the continued desire to emulate the culture of the continent led to a long-standing tradition of writing in Chinese, which was favored for formal and literary purposes for many centuries.4