ひゃひゅひょ — The HY Row
Why the HY yōon?
The HY yōon group is dominated by one number word — but that one is everywhere. ひゃ anchors 百 (hyaku, "one hundred"), one of the most-used number words in spoken Japanese, plus its compounds (百貨店 hyakkaten, "department store"; 百科事典 hyakkajiten, "encyclopedia"). Note: 100 takes phonetic shifts when prefixed by certain numerals (三百 sanbyaku, 六百 roppyaku, 八百 happyaku). ひゅ is the rarest yōon in the entire chart — almost exclusively in loanwords (ヒューマン, hyuuman) and wind onomatopoeia. ひょ shows up in 表 (hyou, "table / chart"), 評価 (hyouka, "evaluation"), 表現 (hyougen, "expression"), and the playful ひょっこり (hyokkori, "popping out unexpectedly").
Pronunciation at a glance
Words you can read with HY combined kana
With every base and diacritic row plus the HY combined kana, you unlock every multiple of 100, plus essentials like 表 (table), 評価 (evaluation), 表情 (facial expression), and the playful ひょっこり. These examples lean heavily on ひゃ, ひゅ, ひょ. Print these as flashcards →
What's next
After HY, the next yōon group is みゃみゅみょ (mya/myu/myo) — the M-row palatalized syllables. The MY family is one of the rarest in everyday Japanese, but it appears in 苗字 (myouji, "family name") and a few loanwords. After MY comes the much more useful RY (りゃりゅりょ), then the dakuten/handakuten yōon.