Not yet reviewed by Pith; the record is open.

We present the XMM-Newton X-ray analysis of 19 X-ray luminous galaxy clusters of low-to-mid redshift ($< 0.4$) selected from the MCXC cluster catalogue in the Hyper Supri%survey as the first work in our series paper. We derive the hydrostatic equilibrium mass and study scaling relations using i) the whole sample, ii) only relaxed clusters and iii) only disturbed clusters. When considering the whole sample, the $Y_{\rm X}$-$M_{\rm tot}$ and $M_{\rm gas}$-$M_{\rm tot}$ relations agree with self-similarity. In terms of morphology, relaxed clusters show a flatter relation in $L_{\rm X,ce}$-$M_{\rm tot}$, $L_{\rm X,bol}$-$M_{\rm tot}$, $L_{\rm X,ce}$-$T$, $L_{\rm bol,ce}$-$T$, $M_{\rm gas}$-$M_{\rm tot}$ and $Y_{\rm X}$-$M_{\rm tot}$. The $L_{\rm bol,ce}$-$M_{\rm tot}$, $L_{\rm X,ce}$-$M_{\rm tot}$ $L_{\rm bol,ce}$-$T$ and $L_{\rm X,ce}$-$T$ relations show a slope $\sim$3$\sigma$ steeper. The residuals in the $M_{\rm gas}$-$M_{\rm tot}$ and $T$-$M_{\rm tot}$ relations and the intrinsic covariance between $M_{\rm gas}$ and $T$ show hints of positive correlation, casting doubt on whether the $Y_{\rm X}$ parameter is a truly low scatter mass proxy. The $M_{\rm gas}$-$M_{\rm tot}$ and $T$-$M_{\rm tot}$ plots color-coded with the offset of the $L_{\rm X,ce}$-$M_{\rm tot}$ relation show these two relations to be brightness dependent but not the $L_{\rm X,ce}$-$T$ relation, suggesting relations involving $M_{\rm tot}$ are biased due to sample selection based on luminosity. Following the work which studied an optical sample and combining our result with literature studies, we find the $M_{\rm tot}$ derived not using mass proxies deviate from $L_{\rm X}$ $\propto$ $M_{\rm gas}^{2}M_{\rm tot}^{-1}$ and $M_{\rm tot}$ based on hydrostatic equilibrium are more massive than what is expected by their relation using caustic masses. This indicates mass bias plays an important role in scaling relations.