Yōon
The yōon (Japanese: 拗音 (ようおん)) is a feature of the Japanese language in which a mora is formed with an added [j] sound (i.e., palatalized) or, more rarely in the modern language, with an added [w] sound (i.e., labialized). Yōon are represented in hiragana using a kana ending in i, such as き (ki) or に (ni), plus a smaller version of one of the three y kana: や (ya), ゆ (yu), or よ (yo).