Hmm, I'm normally fine with one-shots but this was too short even for me. I can see what the artist was going for, but there wasn't enough interaction between the couple to really get into it.
Also, in case anyone was confused this was about the Kuchisake-onna, a Japanese urban legend about a woman with a slit mouth. Although this lady here seems to be a different Kuchisake-onna from the one in the legend - probably why she said she'd try "To copy a popular thing Senpai once did".