Who would succeed Japanese PM Shinzo Abe if he stepped aside due to health concerns?

If Shinzo Abe resigns over health problems, the next Japanese prime minister might tweak policy on everything from China ties to monetary policy, without making drastic changes.Since taking power in 2012, Abe has touted unprecedented monetary easing and a flexible fiscal policy to revive the economy – a package dubbed “Abenomics”. He has worked to build a personal bond with US President Donald Trump, while at the same time seeking to smooth over ties with Japan’s biggest trading partner, China…

from South China Morning Post https://www.scmp.com/news/asia/east-asia/article/3098862/who-would-succeed-japanese-pm-shinzo-abe-if-he-stepped-aside