First, a clarification: “Hikaru Nagi” isn’t a single person. In most accounts, the name refers to a phantom-like collective—or a recurring alias used by a group of train enthusiasts turned provocateurs. The term “Nagi” (凪) means calm , while “Hikaru” (光) means light . Ironically, the group is anything but calm.
Another angle: maybe "Train Gang" refers to a subculture or a specific phenomenon in Japan. However, I'm not aware of any prominent groups by that name. It's possible that the user is referring to a small community or a niche online group. video title a japenese hikaru nagi train gang updated