Personally, Liu Chuan is a man-show figure. He was very supportive when someone cheered for him. There is no expression on his face, but he is actually quite happy.

After the slam dunk to nationals, there was no painting. In fact, there is nothing to draw after that. I don't know where you heard that Liuchuan likes Sister Sakuragi, but there is no role of Sister Sakuragi in the cartoon.