The word "地雷" (landmine) originally means "to step on a landmine"
(i.e., to encounter trouble or be hurt).
Specifically, the term "地雷系" (Zirai-kei) started to be used on social media
to refer to a fashion style that conveys a "fragile and unstable, yet mysterious and dark" atmosphere,
as if carrying emotional burdens. This style includes elements such as "sickly cute" (病みかわいい),
which evokes sadness and fragility.
By expressing emotional instability and a delicate impression,
it is seen as evoking the "danger of stepping on a landmine,"
leading to the widespread use of the term "Zirai-kei."
Zirai-kei fashion became popular mainly in areas like Kabukicho and Shinjuku in Japan,
and it is said to have spread from there.
Kabukicho and Shinjuku are known as the centers of host clubs,
where the emotional struggles of the women in those areas are reflected in their fashion.