So you are comparing Japan's military occupation of China with the European colonialism of Africa, and say that European colonial powers haven't apologised for their colonialism. I am not sure whether the European apologised for colonialism (which European country and for what colonies ?), but it seems that nobody is complaining about that now. As I said in reply to your post
here, former European colonies have usually kept good relations with their former colonists, as the (British) Commonwealth of Nations shows. The reasons are that the Europeans behaved very differently from the Japanese Imperial Army, and gave the colonised countries more than they destroyed.
African countries, as you mention them, got their first railways, schools, libraries, modern government, etc. thanks to the European. When they were granted their independence in the 1960's, the situation became much worse than under European rule, with dictators getting dirtily rich while their people was starving, and mass genocide as in Rwanda and Congo. Well, we could say that the situation in China under Mao wasn't much better, but it is partly because the Japanese created chaos by destroying the country from 1937 to 1945, then partly because of the cold war (China was on the wrong side, with Russia, and cut itself from the rest of the world). African countries got support from Europe, billions of USD in ODA, charity, etc. but it always went to corrupted leaders, and the situation only got worse. Contrarily to China, which has a long history as a civilised nation, most of Africa didn't have any countries before the European came. Their technology and social system was almost utterly primitive. So they received a lot from the Europeans.
What good things did Japan do for China when it occupied it ? I would rather compare Japan's occupation of China to Germany's occupation of Poland or some other Eastern European countries, although on a smaller scale. It was a
war, with massacre, plunder, rapes and biological warfare experiment, not a paternalistic colonialism with mainly commercial and moral (religious) goals. Manchuria was quite different, and maybe closer to a European
protectorate (eg. Morocco, Uganda, Egypt...), as it was officially an independent state. Korea was a real colony, directly governed from Tokyo.