Answer:
By opening interaction with western nation.
Explanation:
In the past, both of these nations were extremely secluded and homogeneous. They strive to produce their own consumption products without any form of trades with another nation.
But they soon realize that it is much more beneficial to be involved in international trades due to the increase of target market and
China started to opened up the possibilities for international relation in early 1800s, and started to show signs of economic growth from that decision. Japan see this, and decided to emulated China in 1854.
That being said, both nations were pretty adamant that they're not interested in any form of colonial relationship with the Europeans. They wanted to maintain complete autonomy over their territories and not afraid to retaliate if the western nations started to show that intention.
