Ryuk, a Shinigami, seeks to escape boredom in the Shinigami Realm by exploring the Death Note. He finds Light interesting due to his experiments and discovers loopholes, but doesn't care about his life or death. Ryuk's actions are motivated by wanting to see something interesting, and his intelligence allows him to be manipulated by Light's ability to understand his desires. Ryuk's addiction to apples is similar to humans' addiction to cigarettes and alcohol, and he experiences withdrawal.