Japanese lost WWII, the loser pay back winner, unconditional.
Here i must point out the ODA (official development assistance) from Japan government, 90% of it to China belong to official loans with low interest. NOT FREE !
Read below documents:
Overview of Official Development Assistance (ODA) to China
ECONOMIC COOPERATION PROGRAM FOR CHINA
Review on Japan's ODA to China
Japan kill ur millions of ppl then provide ur country ODA by 35billion $$ loans with low interest,
DEAL? 35billion $$ Japan's loans could built today China ?!
At the same time China is the N.o1 biggest foreign market for Japan over U.S.