The Daiwa Expert Seiryu 45 is an ideal rod for modest fish in middle sized streams. It is a tip flex rod that could be described as a soft 7:3.
The rod has a cork grip. The grip is short for a tenkara rod, but no shorter than the grips on the Nissin Air Stage Fujiryu Tenkara rods. The grip makes the rod heavier than a seiryu rod of the same length, but the extra weight is all right at your hand. The rod feels "different" than a seiryu rod, but it doesn't feel heavy.
Daiwa recommends a wide range of tippets - from a fairly standard tenkara tippet of 5X all the way down to a "zero" keiryu tippet of 10X. The rod has a firm enough midsection that you could easily break 10X on the hook set if you aren't very careful, but the tip sections are soft enough to protect the light tippet if the fish are under 7-8". The midsection is firm enough that with 5X tippet, you should be able to land 15-16" fish.
I can certainly see why Daiwa would describe the Expert Seiryu rod as an "adult play" rod. It is very clearly a rod that will be fun to play with.