seems an like urban legend to me – exacerbated by the apparent similarity of a Japanese Maple leaf in appearance to a cannabis leaf. A bar owner in Ireland planted some outside their bar; and some irate anti-drug campaigner made a big fuss!
They are sometimes mistaken – furthermore some Asian works of art show the two leaves together, probably merely because the artists thought it looked good.
http://www.cannabisculture.com/articles/101.html
it is an attractive tree (either as a bonsai or full size) – but not a source of a quick high.
