Japanese wordplay

Japanese wordplay relies on the nuances of the Japanese language and Japanese script for humorous effect.

Japanese double entendres have a rich history in Japanese entertainment, because of the way that Japanese words can be read to have several different meanings and pronunciations (homographs). Also, several different spellings for any pronunciation and wildly differing meanings (homophones). Often replacing one spelling with another (synonyms) can give a new meaning to phrases.

Goroawase
Goroawase (語呂合わせ) is an especially common form of Japanese wordplay whereby homophonous words are associated with a given series of letters, numbers or symbols, in order to associate a new meaning with that series. The new words can be used to express a superstition about certain letters or numbers. More commonly, however, goroawase is used as a mnemonic technique, especially in the memorization of numbers such as dates in history, scientific constants, and phone numbers.

Numeric substitution
Every digit has a set of possible phonetic values, due to the variety of valid Japanese (kun'yomi and on'yomi), and English-origin pronunciations for numbers in Japanese. Often readings are created by taking the standard reading and retaining only the first syllable (for example roku becomes ro). Goroawase substitutions are well known as mnemonics, notably in the selection of memorable telephone numbers for commercial services, and in the memorization of numbers such as years in the study of history.

Mnemonics are formed by selecting a suitable reading for a given number; the tables below list the most common readings, though other readings are also possible. Variants of readings may be produced through consonant voicing or gemination, vowel lengthening, and the insertion of the nasal mora n (ん).

As mnemonics
1492 (the year of discovery of America) can be memorized as: ''iyo! kuni ga mieta! (derived as follows: i (1) yo (4)! ku (9) ni (2) (ga mieta)!''), meaning: "Wow! I can see land!" or i (1) yo (4)! ku (9) ni (2), It's good country.

23564 (23 hours, 56 minutes, 4 seconds, the length of a sidereal day) can be read "ni-san-go-ro-shi", which sounds very similar to "nii-san koroshi" (兄さん殺し), or in English killing one's brother.

3.14159265 (Pi) can be read "san-i-shi-i-ko-ku-ni-mu-ko"(産医師異国に向こう), meaning "An obstetrician goes to foreign country.".

Other examples
4649 "yoroshiku" (derived as follows: "yo" (4) "ro" (6) "shi" (4) "ku" (9)) means: "Nice to meet you."

18782 can be read "i-ya-na-ya-tsu" (いやなやつ) – meaning unpleasant guy

37564 can be read "mi-na-go-ro-shi" (みなごろし), meaning massacre, or kill them all.

893 can be read "ya-ku-za" (やくざ) or Yakuza. It is traditionally a bad omen for a student to receive this candidate number for an examination.

573 stands for "ko-na-mi" or Konami. This number appears in many Konami telephone numbers and as a high score in Konami games.

765 stands for "na-mu-ko" or Namco. Derivatives of this number can be found in dozens of Namco produced video games. It is also the central studio of The Idolmaster and its sequels.

.59 "ten go ku" is the title of a song from the Konami game beatmania IIDX. "Tengoku" (天国) means heaven.

3923 "san kyu ni san", or "Thank you Nissan!" (Nii-san means elder brother, so it is more like "Thank you, brother."). Found in the Online Comics of NBC TV Show Heroes, for which Nissan is a sponsor.

634 "mu sa shi", intentionally set the height of Tokyo Skytree sounds like Musashi Province or Miyamoto Musashi, easy to remember among Japanese.

801 "ya o i" or yaoi, homosexual themed manga typically aimed at women

39 can be read as "san-kyu" (thank you); or "mi-ku", as in Hatsune Miku

15 is "jū go"; but 1 5 is "Ichi Go" or Ichigo Kurosaki, the main character in Bleach. Ichigo is also "Strawberry" in Japanese

315 is "san-ichi-kyuu"; but 3 1 5 is Sa-I-Ga, as in Kamen Rider Psyga, hence the code to activate the henshin.

913 is "kyu ichi san"; but can also be read as "ka-i-sa", as in Kamen Rider Kaixa, hence the code to activate the henshin. An anagram of this is 193. it was intended to be read as "ichi kyu san", but can also be read as "I-Ku-Sa" as in Kamen Rider IXA or Iku-san. In the former's case, this is the code to activate Rising Mode. In the latter's case, it also means Iku Nagae.

23 can be read as "ni san", motor manufacturer Nissan frequently enter cars numbered '23' into motorsport events.

40 can be rendered as "ju yon" or "yon rei". But it can also be rendered as "four zero", with the first two syllables used to create the title Kamen Rider Fourze.