As promised, here it is.
Most don’t believe the legend of the Mirror’s Portal because they do not believe that the Mirror does or once did exist. But this legend is proven true when three boys from our world, Khanamaru, Takeshi Nakamura, and Usagi, are brought to the land of Kantour via the Mirror’s Portal, and learn that an evil warrior named Gaasu is threatening the peaceful land. The danger is so great that the princess has gone into hiding and no one knows where or who she is. The boys are told that no one in Kantour will dare fight Gaasu so they have been chosen for the task and they accept the challenge. Though they are warned that the task will be difficult and dangerous, no one could imagine just how difficult and dangerous it becomes.
With the help of three Dalmatians named Anaberu, Dekusutaa, and Dugan, a Clydesdale called Galan, and their mentor, Kurisutaru, the boys begin their training so that they will be ready to embark on this dangerous mission when the time comes. But when the city becomes too dangerous, the princess’ identity is revealed to the boys and they find that they have to escort Princess Sukaaretto to the country for safety. However, the tables turn when Gaasu ambushes them on the trail. When he disappears, it is quickly noticed that Kurisutaru is gone as well and the boys quickly figure out that it is not Sukaaretto, but Kurisutaru who is the Lost Princess of Kantour.
From this point, things seem to spiral out of control. The boys are sent back to our world only to discover that Gaasu has launched war. They don’t understand how Gaasu could come to our world—unless Kantour’s Whispered Secret is at least partially true.
Now begins a whirlwind of different events. The boys must search for dragons, steal a map, rescue Kurisutaru, and stop Gaasu. They believe that Gaasu is dead and they have succeeded until he uses the Mirror to exile them in our world. Now they have to find a way to get back to Kantour, but that way involves robbing the Masutomi Geology Museum in Kyoto. Once they’re back in Kantour they have to find Dekusutaa and Dugan and rescue Galan. From there they have to travel through the secret tunnels to get inside the Great Palace before the Crowing Day so that they can prevent Gaasu from crowning himself king. But Khanamaru, Takeshi, and Usagi have no idea that there is another villain besides Gaasu, and it is someone who they supposed to be dead, and someone they never supposed to be evil.
So, there's my manga synopsis. What do you think?