If you work using corel draw, there's an option that you can set your pen tool (bezier tool) in to round style. It's mean that your line, specially the corner, not in square corner, it will be round and smooth corner.
You can check the mustache. It's not the nice line because the end of the lines is square enough. But it's already in curve line, so, I cannot make a change. Yeah, just enjoy the file and download it below.
You can also download a lot of doraemon vector in one file (quite big file) in AI file (Adobe Illustrator) below.