China

China is a huge country, I couldn't agree with you more. Depending on where in China we look there will be slight varieties of what is considered to be beautiful. What would be considered beautiful in North China might not be considered so beautiful in the South part of China. So I'm here to give you some general traits which they find to be beautiful. 

White skin. How we have products which help us with tanning or give us a tan-like glow, in China most of the products contain whitening agents. There's even an expression 白富美 (bái fù měi) which is meant to jokingly describe the perfect Chinese woman: white, rich, beautiful. 

Full lips. Before Kylie Jenner took over the internet, Chinese were already putting a high value on their full lips. Fuller lips are thought to bring in good luck and be attributed to a fun-loving, warm, and expressive personality. On the other hand, those with thin lips were thought to be colder, more determined, and more calculating – qualities that are not usually considered attractive in women. 

Height (in men). Just like the “ideal” woman is “白富美,” the ideal male is “高富帅(gāo fù shuài.)” This means “Tall, rich, and handsome” – not too far off from the Western ideal of “tall, dark and handsome.”. Taller men were also thought of being stronger which meant they would be capable of protecting and taking care of their families, something which women find attractive. Although... this standard doesn't differ from the general beauty standard.

Double eyelids. Monolids are thought to be unattractive as they make the eyes seem smaller. In China around 50% of the female population is born with a monolid and many choose cosmetic surgery for this. Contrary to popular belief, Asian women do not go under the knife to make their eyes more “Western.” The large-eyes beauty ideal started centuries before Western civilization. In Chinese culture, large eyes are thought to be more womanly, innocent, and doll-like, and align with some of the expected qualities of women in past times – submissive, obedient, and feminine. 

Japan

Clear skin is considered a beauty standard pretty much everywhere in the world but in Japan the lighter the skin tone, the more beautiful you are to be considered by the people there. Pure, white, unblemished skin is extremely coveted here. 

A high-bridged nose. In Japan, and mostly anywhere in South-East Asia, a big nose with a high bridge is considered to be very beautiful and 'exotic' looking. 

A small, slim face. Again, one of the beauty standard in pretty much most of the countries in South-Est Asia, having a small face is considered ideal and beautiful. The smaller it is, the more beautiful. It's become a problem, cause there are a lot of women who will shave off parts of their facial bone structure in order to make it look slimmer and smaller. 

Thin, petite bodies. It's a well-known fact that SE Asians are generally thinner than Europeans or Americans. And entertainment has an even heavier influence now and desires slimmer and slimmer.
ボンキュッボン (Bonkyubbon) is an expression which means large bust, slim waist, and slightly curvy hips. 

Double eyelids. Most SE Asians have monolids or even partial lids. They find having double eyelids beautiful. It opens your eyes and makes them rounder and bigger and that's something which they generally like. There are many methods of getting double eyelids be it with transparent sticky tapes, eyelid glue or even surgery, a lot of SE Asian men and women will get these procedures done in order to have the desired double eyelids

And last but certainly not least: a polite personality. You'll ask 'what does personality have to do with beauty?' Let me answer that question before you can ask it. In Japan, no matter how beautiful you are, if you're not polite or respectful, neither men nor women will give you a chance, they'll not glance at you twice. For them, respect and politeness are just as important as outer beauty, if not even more. Beauty for them comes from the inside as well as the outside

South Korea

South Korean beauty standards are pretty easy to guess. All you have to do is look at all the k-pop idols and see all the common points. And by no means are they few. 

The First thing that Koreans tend to observe is the size of someone’s head aka proportion. For head size, the smaller is the better. the ideal head: body ratio is 1:8 and it applies to both male and female.

Next, the forehead. A round forehead is ultimately considered more attractive than a sunken forehead or one with a prominent and strong brow bone. 

Moving on to eyes. High brows with lots of space between the eyes and the brows are considered beautiful as they give a more open image. Likewise, sunken lids are considered elderly (even if many young people have it too) and a double eyelid is considered desirable and very beautiful and it is also considered a must, for the same reason that it makes your eyes bigger and more open. Under-eye bags, also known as aegyo-sal because it's considered cutesy and youthful.

The ideal shape of the nose is medium to high bridge with a round pointy tip. A very high nose in a girl is considered unnatural and unattractive while a flat nose is considered unattractive  as well. 

The chin or well, face shape, should be a sharp v-line, but keeping it natural. However, it's not as raved about as before, someone with a square jaw or a round jaw could also be considered attractive as long as they meet the other beauty standards. 

Pale skin is already useless to mention because it seems to be a trend in almost all of Asia. Whitening products being available everywhere. Celebrities especially being expected to have white skin and even bashed for having darker skin (ie: N from Vixx, Kai from EXO, Hyorin from Sistar) but we love them nonetheless. And they love themselves. And that's all that matters!