Ohranger had the lowest ratings in the franchise's history until Go-Busters. The toy sales, however, were actually really good.

The series is a lot more serious that you might think. It was meant to be a parody series, but its undertones are quite serious. Just look at the Zeonette's crush on Red Racer.

But wait, weren't Kyoryugers even lower? And I'm not sure how Toqger did and Ninninger currently but I'm sure they're in the same boat.

But unlike Go-Busters, the toy sales for Kyoryu, Toq and Ninnin are much better.

The problem is, we can't be sure why they have low ratings. It could just be the time the series air in that is causing it to have low ratings. It's on early in the morning, and with DVR and the internet, there is no reason to watch something that early if you aren't up already. The ratings don't account for those watching it on DVR or streaming, so of course the ratings are going to be lower.

Still waiting on my Kamen Rider dvds. Gimme Ryuki dammit!

Other shows in the past have air early Sunday mornings in the past and did fine before with ratings. I think low ratings is likely because there is not many kids watching the shows these days because the amount of kids that like these shows are lower compare to 10-30 years ago. Not to mention Yokai Watch is really popular with kids over in Japan and has become the new Digimon (Pokemon rival featuring kids and cute/cool monsters).

I also think lack of interest from older viewers also hurts ratings since it seems like most older fans don't seem have much interest in the newer shows. Japan has their good share of purist fanboys who act like the new shows suck and how everything in the past is good. I know kids are always the main target audience, but having older people tune in on watching the shows also helps.

Just had a thought - I hope this is going to have the movie on it as well and not just be the TV episodes.

Take note, some of what follows may be subject to conjecture.

Carranger is something like "Akibaranger before Akibaranger". It's something of a parody of Sentai and has numerous "hokey-jokey" elements to it. Ohranger started serious then took a step back, supposedly because real life events in Japan were upsetting, like the gas attacks in the subways during the '90s (this might require a little research to determine timing and cultural effects).

Hope it helps.

Go-Busters came before Kyoryuger, hence why I had the word "until" in that sentence. Every other Sentai series after Ohranger had higher ratings until Go-Busters.