Here's a sketchbook by Foo Swee Chin, aka FSc, a fellow Singaporean. The style of her art is very different from other Singapore artists that I know of. There's this Tim Burton-ish look mixed with Japanese manga style that I can't quite explain.
Extended Psychoneurosis is a collected of ballpoint pen sketches from 2012 and 2014. The sketches are very loose, sketchy and almost all are character art. There's a moody, broody look to most characters. The ballpoint pen style is interesting and the drawings feel very impromptu, and hence the style it leads to.