hiro ryuu is how you pronounce it. go to some Japanese sites to find out more!
The Japanese word for Dragon is "Ryuu"
Doragonfurūtsu
ドラゴンストライキ
ryu no ha
Kagami Ryū
Doragon iki
'Kinzoku no ryuu'.
ginryu
ryu-ken
to say dragon in Japanese is 龍 and it is read ryuu hope this helps :)
'Small dragon' would be 小さい竜 (chiisai ryuu) in Japanese.
ダークドラゴン (daaku doragon)