Passage: Japanese family names are also usually read with kun'yomi: 山田 Yamada, 田中 Tanaka, 鈴木 Suzuki. Japanese given names often have very irregular readings. Although they are not typically considered jūbako or yutō, they often contain mixtures of kun'yomi, on'yomi and nanori, such as 大助 Daisuke [on-kun], 夏美 Natsumi [kun-on]. Being chosen at the discretion of the parents, the readings of given names do not follow any set rules, and it is impossible to know with certainty how to read a person's name without independent verification. Parents can be quite creative, and rumours abound of children called 地球 Āsu ("Earth") and 天使 Enjeru ("Angel"); neither are common names, and have normal readings chikyū and tenshi respectively. Some common Japanese names can be written in multiple ways, e.g. Akira can be written as 亮, 彰, 明, 顕, 章, 聴, 光, 晶, 晄, 彬, 昶, 了, 秋良, 明楽, 日日日, 亜紀良, 安喜良 and many other characters and kanji combinations not listed, Satoshi can be written as 聡, 哲, 哲史, 悟, 佐登史, 暁, 訓, 哲士, 哲司, 敏, 諭, 智, 佐登司, 總, 里史, 三十四, 了, 智詞, etc., and Haruka can be written as 遥, 春香, 晴香, 遥香, 春果, 晴夏, 春賀, 春佳, and several other possibilities. Common patterns do exist, however, allowing experienced readers to make a good guess for most names. To alleviate any confusion on how to pronounce the names of other Japanese people, most official Japanese documents require Japanese to write their names in both kana and kanji.Chinese place names and Chinese personal names appearing in Japanese texts, if spelled in kanji, are almost invariably read with on'yomi. Especially for older and well-known names, the resulting Japanese pronunciation may differ widely from that used by modern Chinese speakers. For example, Mao Zedong's name is pronounced as Mō Takutō (毛沢東) in Japanese, and the name of the legendary Monkey King, Sun Wukong, is pronounced Son Gokū (孫悟空) in Japanese.

Question: What is one part of the mixture used in the creation of Japanese surnames?
kun'yomi