Japanese Plum

We bought a Japanese Plum tree only a couple of years ago, and it is doing very well.  This time, we dug an extra large hole to plant into.  Last year I got one plum, to sample, which was a nice surprise.  This year, it is fairly loaded with fruits, although many of them look scarred, so I don't know if that is some insect damage, or ...?  Anyhow, today I thought one of the plums looked dark enough to sample.  When polished, it looked like this:

The flesh is VERY red, mild (I'd prefer it a bit more punchy) but sweet, and the fruit clings to the stone, so the best way to eat these little sweeties will be to pop them into your mouth, then spit back the stone.  This little tree was definitely a good investment.