I'm making a japanese exam and I need to write in the same character two ruby (one up and one down).
I'm not sure how to make it.
First, I had to change rubysep redefining for all document:
\renewcommand{\rubysize}{0.7}
\renewcommand{\rubysep}{-0.1ex}
With these parameters I can write over the "Kanji" I want but need to add more text in the inferior part. (I can change \rubysep to -9ex from the beggining but I will have the opposite problem

I thought to use \newcommand to create a new macro, working in the same way as \ruby but with \rubysep{-9ex}.
Anyway, it doesn't work because I'm not sure how to use \rubysep again.
\newcommand{\rd}[2]{\rubysep{-9ex}\ruby{#1}{#2}}

I need some help please.
Thank you so much for your time.