  Understanding of massive cluster formation is one of the important issues of
astronomy. By analyzing the HI data, we have identified that the two HI
velocity components (L- and D-components) are colliding toward the HI Ridge, in
the southeastern end of the LMC, which hosts the young massive cluster R136 and
$\sim$400 O/WR stars (Doran et al. 2013) including the progenitor of SN1987A.
The collision is possibly evidenced by bridge features connecting the two HI
components and complementary distributions between them. We frame a hypothesis
that the collision triggered the formation of R136 and the surrounding
high-mass stars as well as the HI & Molecular Ridge. Fujimoto & Noguchi (1990)
advocated that the last tidal interaction between the LMC and the SMC about 0.2
Gyr ago induced collision of the L- and D-components. This model is consistent
with numerical simulations (Bekki & Chiba 2007b). We suggest that a dense HI
partly CO cloud of 10$^{6}$ $M_{\odot}$, a precursor of R136, was formed at the
shock-compressed interface between the colliding L- and D-components. We
suggest that part of the low-metalicity gas from the SMC was mixed in the tidal
interaction based on the $Planck/IRAS$ data of dust optical depth (Planck
Collaboration et al. 2014).
