It's always sad to see how a film as fun as this was released once it was outside of Japan. The dubbing for the A.I.P. print is abysmal compared to some of their other treatments of similar titles of the time, and the pan and scan cropping of the film destroys much of the majesty of the film itself. If you'd like this version of the film, however, it's being released soon by Retromedia (if I'm not mistaken).
But, thankfully, all is not lost. Toei Co. Ltd., a studio known more for it's sentai than for anything else, saw to it that this title, along with several other films that are nearly impossible to find, was released to Laserdisc in 1993. While currently out of print, the laserdisc is not impossible to find. If you have a player and some extra cash (while not impossible to find, a copy runs anywhere from $45 to well over $100 these days) I highly recommend it.
Kairyu Daikessen tells the story of a prince who's kingdom is over-taken by an evil warlord sometime in medieval Japan. A hawk sent by a kind wizard saves the young prince from a group of ninjas and a giant dragon that has killed off the rest of the royal lineage. The boy grows up with the wizard as his surrogate father and mentor. Eventually the prince goes out on his own to take back the kingdom, facing ghosts, ninjas, and an evil wizard along the way. The conclusion is an all out battle between the good prince and the evil wizard, who have transformed themselves into (respectively) a giant frog and a dragon.
As the other two reviewers have noted, the influence of this film on Star Wars is fairly obvious, though the character genders are reversed (the Luke Skywalker of the story is female while the Princess Leia is male). The special effects sequences are very dated but were very well managed for the time. The action sequences are imaginative and plentiful. The monster suits for the ending of the film are based on traditional Japanese art renditions of dragons and frogs. Overall, this is a very fun film, though it is infinately more enjoyable if viewed in its original format. I'm still hoping for a fully restored Region 2 dvd of the title to be released.