Ha (hiragana: は, katakana: ハ) is one of the Japanese kana, each of which represent one mora.

They are also used as a grammatical particle (in such cases, they denote [wa], including in the greeting "kon'nichiwa") and serve as the topic marker of the sentence.

In the Sakhalin dialect of the Ainu language, the katakana ハ can be written as small ㇵ to represent a final h sound after an a sound (アㇵ ah).

[1] This, along with other extended katakana, was developed by Japanese linguists to represent sounds in Ainu not present in standard Japanese katakana.

The Hiragana は is made with three strokes: The Katakana ハ is made with two strokes: The hiragana は is read as "wa" when it represents a particle.