Christ, Kenichi Endou is in a lot of movies! But, he is underappreciated. In everything I've seen him in he has a really small part -- at times he seems almost like an extra!
Takashi Miike regularly casts him in his movies. Endou's the main character in the disgusting "Visitor Q." Endou's a brilliant actor -- so good that I could barely look at him for a couple of days after watching that. He also had a funny role as the sidekick to Riki Takeuchi's thug in "Deadly Outlaw Rekka," and he was also in (and the only part I liked of) Azumi.
As far as tokusatsu, Endou played Vulgar in the Dekaranger movie (alongside Dairanger's Gara and Zydos!) and was in an episode of Exceedraft.
Come on, it's kinda catchy in a way. As for the worst song ever? That one does come from Zyuranger, and it's that God-awful Daizyujin no Uta. Now, THERE is a horrible, intolerable piece of musical garbage. If you haven't heard it, consider yourself a blessed man. Dragon Caesar no Uta isn't much better on that soundtrack either.
I'll defend the OP theme only for Kenta Satou, but I've always hated that song for being so peppy. It actually suited Zyuranger, but the ED theme didn't at all. I was surprised how much the audience dug it at Super Sentai Spirits '04. To tell the truth, as much as I like Hironobu Kageyama, I think Zyu's predecessor, Jetman had a shittier OP theme that didn't match the show at all.
I think, again, the worst OP theme goes to Magiranger. **** composition, **** singing, **** lyrics and it's about five minutes long. Ugh, the song has an annoying pattern to it. "Go fight Mag - Mag - Magiranger/Shin-OH!-jit-su fuchair! OK - allrye." Hideous song. And Takafumi Iwasaki, one of those nad-less singers Japan favors, wasn't in tune once. That's what happens when you choose someone who wasn't a singer prior to giving them a song that will be heard for 50 episodes an entire year! Satou was at least trained to be a song and dance man.