This category lists languages which use the Japanese syllabaries (alias for Hiragana + Katakana) script (or syllabaires japonais (alias pour hiragana + katakana) in French), coded Hrkt or 412 in ISO 15924 since 2011-06-21, supported in Unicode since version 1.1 with alias Katakana_Or_Hiragana. See also wikipedia:en:ISO 15924:Hrkt.
You can render that script on your system with the following fonts (in order of coverage) : 'Noto Sans CJK JP', sans-serif.
This is actually a mix of several scripts: Katakana (ISO 15924: Kana), and Hiragana (ISO 15924: Hira), and a simplified subset of the scripts normally used for Japanese (ISO 15924: Jpan), but without Han (ISO 15924: Hani) in Kanji style which is transcripted to Hiragana or Katakana.
This script is useful in several Japonic languages (including Japanese) to provide approximate phonetic reading of traditional Kanji characters (because the phonetic traits that compose a part of these Han characters, even if they were adapted to the Kanji style, may be suitable for Chinese but not for Japanese, and there's no way to make such conversion without performing a lookup in a large dictionary), or when rendering all the needed Kanji is technically not possible, or to provide approximate phonetic reading of other non-Japanese scripts. It is also very useful for early learners of the Japonic languages, before they are trained to read the traditional Kanji characters.