In many anime, the girls there have fangs.
Why are fangs of girls so common in anime?
In many anime, the girls there have fangs.
Why are fangs of girls so common in anime?
They're called Yaeba. Wikipedia says:
In Japan, yaeba (八重歯, "double tooth") are human teeth, especially upper canines, with an uncommonly fang-like appearance. Yaeba most often refers to a tooth overlapping another tooth or protruding from higher in the gum. In Japan it is perceived as a sign of youthfulness and natural beauty. In 2013 it had become a trend where teenage girls would undergo dental procedures to cap the upper canines.
In addition to BCLC's answer, the girls in the The Helpful Fox Senko-san are kitsune, aka fox spirits.
Foxes have fangs. They, along with many of the other fox/wolf/cat/dog-human hybrids that show up in anime, have fangs as part of their "not-fully-human" character design.