Japanese curry has similar flavors to Indian curry and is made with similar spices, garam masala and curry powder.  However the main difference I find is that Japanese curry is less spicy and a little bit sweeter than many Indian curry dishes.   It is commonly served up with meat and veggies either in a stew or over a breaded pork or chicken cutlet called Katsu.  It is less common to see the curry served up with lentils or other legumes as many Indian curries are prepared.