  The analysis of $e^{+} e^{-} \to \text{invisible} + H(\to \mu \mu)$ at a next
generation linear collider presents an opportunity to study the coupling of the
Yukawa couplings of the second generation in a clean environment. We give an
overview over the experimental challenges of this analysis at a collision
energy of 500 GeV and present an outlook to the results of the analysis at a
collision energy of 250 GeV.
