The standard Japanese dialect "R" is a voiced alveolar
. A flap is like a stop/plosive
(/p/, /t/, /k/), except the passage is closed for a much shorter time.
Flaps are often found in non-southern American English
as allophones of /t/ and /d/, such as in bitt
er, and ladd
In short, it is never an American English "R" sound.
Sometimes, such as when spoken slowly, or at the beginning of a word, or in songs, the Japanese "R" may be pronounced as a lateral
"L" sound by some people.
In the mostly extinct dialect of downtown Edo
, the "R" is sometimes trill
ed. In anime, a character may switch to this form of pronunciation when shouting angrily, to depict a rude Edokko
stereotype. One thing to keep in mind when watching anime is that the Japanese spoken in it may not accurately depict vernacular