mise公式ページにasdfからの移行方法が載っていた。

How do I migrate from asdf?

First, just install mise with mise activate like in the getting started guide and remove asdf from your shell rc file.
Then you can just run mise install in a directory with an asdf .tool-versions file and it will install the runtimes. You could attempt to avoid this by copying the internal directory from asdf over to mise with cp -r ~/.asdf ~/.local/share/mise. That should work because they use the same structure, however this isn't officially supported or regularly tested. Alternatively you can set MISE_DATA_DIR=~/.asdf and see what happens.

https://mise.jdx.dev/faq.html#how-do-i-migrate-from-asdf