  If one removes any \emph{ad hoc} symmetry assumptions, the general two Higgs
doublet model should have additional Yukawa interactions independent from
fermion mass generation, in general involving flavor changing neutral Higgs
couplings. These extra couplings can affect the discovered Higgs boson $h$
through fermion loop contributions. We calculate the renormalized $hZZ$
coupling at one-loop level %by on-shell and minimal subtraction scheme, and
evaluate the dependence on heavy Higgs boson mass and extra Yukawa coupling
$\rho_{tt}$. Precision measurements at future colliders can explore the
parameter space, and can give stronger bound on $\rho_{tt}$ than the current
bound from flavor experiments. As a side result, we find that if
$\rho_{tt}\cos\gamma < 0$, where $\cos\gamma$ is the exotic Higgs component of
$h$, the $\rho_{tt}$-induced top loop contribution cancels against bosonic loop
contributions, and one may have alignment without decoupling, namely
$\sin(-\gamma) \simeq 1$, but exotic scalar bosons could have masses at several
hundred GeV.
