Wagakki band are great.
Babymetal has already been mentioned, so other bands that might be suitable:
Blood Stain Child is a great melodic death metal with electronic/trance influences and their Epsilon album at least is in English.
Doll$boxx is a combination band with Fuki (formerly of powermetal band Lightbringer) and hard rock band Gacharic Spin. Take My Chance is probably their most famous song that did the rounds a few years ago in English circles.
High and Mighty Color were a hard rock band, best known for Ichirin no Hana, used as the opening to the anime Bleach.
Tengger Cavalry are a Mongolian folk death metal band that I quite enjoy, combining metal with traditional Mongolian instruments and throat singing.