
The shorter Daiwa Hinata rods are microfishing rods. The 3 foot rod really is just for micros. The tanago that people catch in Japan are no more than a few inches long.
The 5 foot rod is a bit more capable, so smaller sunfish, most creek chubs and even 4-5" trout should be no problem. The only problem is that you can't be sure that you will catch ONLY 4-5" trout. I would highly recommend using very light tippet 8X or 9X.
The 7' rod is more capable yet, and I suspect 6-8" fish would not be a problem. I would still suggest using a light tippet unless you are sure you will not hook larger fish.
If you are sure that you will not hook unexpectedly large fish, a 3' or 5' tanago rod is just an awful lot of fun to fish with. They are so small. They are so light. It's like fishing with Harry Potter's wand or a symphony conductor's baton.