Ryuk

Ryuk is bored with the activities (or lack thereof) of the Shinigami realm, Ryuk obtains a second Death Note and drops it in the human realm for someone to find, hoping to amuse himself. He deliberately writes the instructions on the front page (in English, which he assumed to be the most popular language in the human realm) so people would understand its purpose. The Death Note is discovered by Light, and Ryuk follows him around for much of the series to see how Light uses it. He also loves the taste of apples, and will eat one whenever he can.

Ryuk is bored with the activities (or lack thereof) of the Shinigami realm, Ryuk obtains a second Death Note and drops it in the human realm for someone to find, hoping to amuse himself. He deliberately writes the instructions on the front page (in English, which he assumed to be the most popular language in the human realm) so people would understand its purpose. The Death Note is discovered by Light, and Ryuk follows him around for much of the series to see how Light uses it. He also loves the taste of apples, and will eat one whenever he can.
