What combination of factors makes japan monsoonal

There are numerous factors. It mostly relies on rough winds coming from all sides and clashing over Japan, mixed with the humid area and heavily clouds that come from the pacific ocean, and also both air and water currents. Everything about Japan's geographic position is great for Monsoons, Typhoons, Earthquakes, and numerous other disasters. 

Earthquake waves that vibrate from side to side and up and down only through solids are known as "seismic waves."hope my answer has you : )

Нет, нужен трамвай, аэропорт, приют. я предлагаю обществу общественной помощи.