I gave up my progress in the current version and wait for the rumored update.
My problem with this game is that I can not find a way (or there is not? I am not sure) to actually train those yukkuris. Scolding seems to do little unless the yukkuri is a very scummy one, and scolding ones with silver or golden sparks usually ends up with them rapidly says thing like "Apologize, quickly" to you even if they are in normal to better mood and not puffing, and will puff up to you easily if you are scolding other yukkuri in their sight. And all yukkuris in the game even the ones with silver or golden sparks tends to make little ones, and there seems to be no way to stop them which is also annoying.