How did you first hear of Babymetal?

I first heard of Babymetal when a song called Sayonara by Wanko Ni Mero Mero was featured on Just Dance 2018 and someone pointed out the song sounds like Gimme Chocolate by Babymetal. I chose to listen to the song for similarities and both songs sounded almost exactly the same instrumentally then I chose to listen to more of their songs, now I'm a fan.