Well, we don't know where in the world you are or where in the garden the plant would go, so it would be tough to opine.

tj

All are welcome to opine away. I'm in Portland OR. Wintercreeper does well here. The pic is another one elsewhere in my garden. The question is more about weather the plant will fit in with the Japanese garden aesthetic..

The aesthetic of a Japanese style garden is less about plant choice as it is about placement. The general guiding aesthetic principles are miniaturization, concealment (and gradual reveal) and asymmetry. But since the wintercreeper is native to Asia, including Japan, there is no reason to think it wouldn't fit in well........it is just a matter of where and how it is used.

"Though inspired by nature, a Japanese garden is an interpretation rather than a copy; it should appear to be natural, but it is not wild."