Nichiren chant (題目)
The Nichiren chant is the words of Namu Myohorenge-kyo, which are recited in the Buddhist religious services held by religious organizations such as Nichiren and the Hoke-kyo Sutra sect. It is also called Odaimoku. Originally, it meant a title and five letters of Myohorenge-kyo (translated by Kumaraju), constituting the translated title (phonetic equivalent) of Hoke-kyo Sutra, and it is called the 'Nichiren chant' even when the two letters of Namu (meaning "of becoming a believer") are added.
Additionally, Odaimoku is sometimes used in the sense of public stance or in nominal terms. They are diverted from the meaning mentioned above.
Both meanings are described below.
What is Nichiren chant?
Nichiren chant (title) of Hoke-kyo Sutra Part 1, Volume 8, Chapter 28, which Kumaraju translated into Chinese characters, consists of five letters, 'Myohorenge-kyo (妙法蓮華経).'
Namu Myohorenge-kyo' means to become a believer in the rule (Buddhism) and the teaching of Myohorenge-kyo (the Hoke-kyo sutra). The training needed to recite Nichiren chant continuously is an ascetic training by which to declare one's belief in and willingness to follow the teaching of the Hoke-kyo sutra. The continuous recitation of five or seven letters of Nichiren chant (which are translated into Chinese characters) is regarded as being the same pious act as reading and practicing all sutras.
Namu' is pronounced 'Namo,' 'Naamo' or 'Namasu' in Sanskrit.
Moreover, from the viewpoint of a person who tries to regard the Nichiren chant of five Chinese characters as Myogo (Amida's name) of the Original Buddha, the way of practice on teaching in five letters of the Nichiren chant is not Volume 8 Chapter 28 but instead the seven-letter Nichiren chant, which is, 'Namu Myohorenge-kyo (南無妙法蓮華経).'
The Tendai sect in the mid-Heian period came to recite the Nichiren chant already affected by the invocation of the Buddha's name, but it simply didn't incorporate Nichiren chant into dharma. Nichiren in fact incorporated Nichiren chant into dharma for the first time.
Details of each sect
The ascetic training to recite 'Namu Myohorenge-kyo' continuously is called 'Shodai (唱題（しょうだい）).'
The Hoke-kyo sects call this 'Shodaigyo (唱題行)' as 'Shogyo(正行（しょうぎょう）)' among various kinds of ascetic training and accord it the highest value. Other types of ascetic training, such as standing under a waterfall, fasting or keeping silent are called 'Jogyo (助行（じょぎょう）)' and are regarded as auxiliary measures.
When believers of the Nichiren sect (mainly Icchi-ha sect) recite the Nichiren chant, they pronounce 'Namumyohorengekyo.'
Believers of the Fujimon-ryu sect (Nichiren Shoshu sect) and Soka Gakkai, which is a lay religion, pronounce 'Nanmyohorengekyo.'
Additionally, in the Buddhist religious services of Nichiren Shoshu sect there is a manner called 'Hiki-daimoku' other than Shodai, in which way each sound is recited longer as 'Na-mu-myo-ho-ren-ge-kyo.'
Although it is not seen now, a few years ago believers of Soka Gakkai recited by extending the sound of 'ren' as 'Na-mu-myo-ho-re-nge-kyo-na-mu-,' but Nikken Hoshu recites it as 'Ren-.'
Meanwhile, Nichinyo Hoshu has recited in the same way after 登座 (unknown at the time he was a chief priest).
Moreover, Buddhists respect the number three, such as three treasures, three studies and three secret processes so that the way of 'reciting the Nichiren chant three times' is used broadly at the beginning and end of Buddhist religious services or memorial ceremonies as a means of showing respect to the main image.
While believers of the Nichiren sect lineage recite each phrase in one breath, such as 'Namumyohorengekyo, Namumyohorengekyo, Namumyohorengekyo,' believers of many Fujimon-ryu sect lineages recite the first and second phrases continuously and recite the third phrase after taking in a breath, such as 'NamumyohorengekyoNamumyohorengekyo, Namumyohorengekyo.'
However, Fuji Taiseki-ji Kensho-kai is an exception among the Fujimon-ryu sect lineages; it adopts an original way of pronunciation as 'Nanmyo, Hoi-re-nge-kyo, Nanmyo, Hoi-re-nge-kyo, Nanmyo, Hoi-re-nge-kyo' and a manner such as 'making a bow twice while reciting 'Nanmyohorengekyo' twice in small voice, reciting the Nichiren chant three times, reciting the Nichiren chant three times again, and bowing twice in the same way as the first' (called 'greeting'), the origin of which is unknown.
The difference between the invocation of the Buddha's name and reciting the Nichiren chant
Invocation of the Buddha's name
The invocation of the Buddha's name by the sects of the Pure Land faith is considered to mean that Amitabha Buddha comes forth from people's mouths in order to let people know they can go to paradise by Amida's true wish, and they place a high value on it as the thing that gives people peace of mind. It is also regarded that living with that peace of mind is a true joy and relief, and that reciting 'Namu Amidabutsu' doesn't require pious acts but is instead a type of training to show gratitude.
Shakanyorai, 'Namu Syakamuni-butsu,' in 'Myogo (Amida's name),' which is recited in the invocation of the Buddha's name, is considered a real person in authentic history. However, there is no other Nyorai in history. For this reason there is a view that denies the existence of 'Amidabutsu' of 'Namu Amidabutsu' as a fictional, imaginary figure.
On the other hand, some people think that 'Amidabutsu' was preached by the historical Shaka as having no figure, being immeasurable and showing eternal 'truth,' so that Shaka's true intension is included in 'Amidabutsu.'
Shodai, reciting Nichiren chant
On the contrary, Shodai in the sects of the Hoke-kyo faith has an affirmative directivity (directivity for this world) to survive in this world, because they think this world is important.
(However, directivity for this world is not inherent with the Nichiren sects but is seen in the Shingon and Tendai sects.)
The Nichiren chant recited in Shodai is the title of a sutra, so that a subject of faith exists as a sutra. Nichiren described that each letter of the sutra should be considered as a gold Syakuson. Even if the letters of a sutra do not look like Nyorai as might be expected, they can at least be seen as letters. Hoke-kyo (Myohorenge-kyo), when written in Chinese characters, can be seen as the enumeration of Chinese characters at least so that its existence as letters gives people peace of mind. Even if the content of a sutra is fictional or a lie, it can be said that the letters of the sutra exist clearly and are the truth.
What is Odaimoku?
Odaimoku is sometimes used in the same sense of Nichiren chant mentioned above, but in other cases it is used without religious meaning.
Odaimoku, in that case, often means one's public stance or nominal terms and implies 'being different from the actual condition.'
For example, it is used such as 'to act seriously, not only with Odaimoku.'