For reference I am 170 cm tall and weight around 48 kg.
I got this shirt in both Ivory and Blue. I got the ivory one in S since M was sold out and the blue one  in M. But the blue one I got seems even smaller than the ivory I got in size S. Thankfully they both still fit me but do keep in mind that you should definitely order at least one size larger than what you would think based on the size chart and what you normally wear, two sizes larger would probably be the best. The fabric itself is top notch and the shirt looks exactly like it's shown in the pictures. I would be even better if they can make the sleeves longer in the next edition so you can also show the details on the cuffs even with the sleeves still reaching your wrists. Overall the quality of the items is very good but definitely keep in mind to size up.