optative sentence
A grammatical term for a sentence that expresses a wish or desire, such as 'May you be happy!' or 'If only it would rain.' Used in linguistic descriptions.
In Japanese, '~masu you ni' is a typical form of an optative sentence.
Compound of 祈願 (kigan, 'prayer' or 'wish') and 文 (bun, 'sentence'). The exact historical derivation is uncertain, but the term is used in modern Japanese grammar to describe optative constructions.