Why are people so aware of the holocoust but unaware of japans atrocities?

i read an article about how japan raped killed and tortured millions of people and also put them in work camps and "experiment camps" where they would take out body parts and limbs and see how long they lived...apparently the japanese people killed more people then hitler so why is it that so many people are aware of hitlers actions but know nothing about what japan has done? shouldnt this be in the history books?