The H-artists finally catching onto Mikuru's birthmark...

great, hope this artist does more

It isn't a birthmark, it only appears in the later chapters (timeline-wise), she has it in the Mikuru-run 0 episode (festival time) but not in chaps 1-4. Could be something that will happen in 5 or 6, we will see.

Damn time skips

>>410
You can see it in a close-up in episode 5 (4), when she's in the maid outfit and Kyon is taking a picture of her cleavage.