At this time, when even a small amount of air precedes the sound of "a," it is heard as "haa." Too weak a burst of air is heard as "a."
Now, to produce "fuu:"
Think of blowing out a candle, and narrow the mouth and put forward "fuuuu." Add "fuu." Otherwise, place the lower lip slightly against the back of the front teeth and say "do-re-mi-fa-so..." Practice pronouncing "Furukawa, Funahashi, Fune ga yuku, Fujisan..." one after the other. Of the ha-sounds, "fuu" is relatively easy to pronounce.
Examples:
Ha sounds: hashioki, hataage, hakoniwa, hakimono, hakuhatsu, hankachi
Hi sounds: higurashi, hikkoshi, hinagiku, himawari, hitogoto, hiruyasumi
Fu sounds: fuusen, furusato, fudatsuki, futokoro, fuusai, fugookaku
He sounds: heikou, heian, heitai, hensen , hekireki, hendensho
Ho sounds: hogaraka, hokosaki, honsai, horafuki, hosomichi, horetahito
Successful examples: