I'm trying to think of any time I've ever seen a style quite like this. I feel like it's on the tip of my tongue...something 4°C maybe? I like it.

it's not quite superflat style, it's like, semi-european to my eyes but then i am not an expert genius

It definitely has a somewhat European style, yet not quite. It's certainly quite unique. Rare in these days.

Aha! I knew I wasn't the only one struggling to identify this type of style!

Yeah, the artist has a unique European style of drawing.

It actually kind of reminds me of Kitarou too, but the line and composition are really different. Definitely influenced by someone European.

I have a friend who used to do lineart like this with a fine-point Sharpie; first I've seen one coloured though!

I spilled my tea after noticing what Chen uses as pillow...