I’ve got a couple of Undead Corporation’s albums. Shunsatu is decent death metal, but Flash Back has a much poppier feel to it. Like Baby Metal, but grown up and serious. So, here’s one of the ones I really enjoy. 

https://youtube.com/watch?v=D7R9yTe6U1E

Lyrics in the YouTube video. Fortunately, they stay in English when the singers switch into Japanese.