Requi has two entrance points. You may have come from Dermos Forest by taking the tunnel to the left of Dermos Castle, or you may have come from Castor Wasteland by taking the tunnel to the south of Castor Fortress. Either way, you will find yourself in a dark green forest populated by large bodies of water. The occupants of Requi include armored axe knights, and mermen who attack you on land and from within the water. They also happen to speak a different language from those spoken in all other regions. The only way you can make sense of what they are saying is to possess the Tongues Liquid.
This will be your first goal (though it may be omitted if you don't care to understand what people are saying), following by a visit to the East Temple where you will find another staff upgrade. There are three other entrances which you must visit and explore in order to find all the things which Requi has hidden about. The final item to obtain, the Resting Bell, is not a mandatory item, and you will need another item in your possession to reach it.
A: Tongues Liquid
This item is very easy to obtained, and is in fact the only easily obtainable item in all of Requi. It requires nothing more than that you visit the south west corner of the region. You will find a chest sitting there waiting to be opened. Once you collect it, the messages spoken to you by the locals will be intelligible. Do note that the cave entrance just above the chest is in fact the only means to visit Maten Mountain, the final region of the game.
B: The Bullet Staff
Your next destination is on the other side of Requi. Near the east side, but still a bit to the south, you will find a pathway that leads to a temple entrance. You will know you have reached the correct entrance if you see a chest in front of the door. The chest will restore your magic.
The inside of the temple is laid out in a long horizontal maze. From the entrance, you can go left or right. To the left, you will find yet another chest which will restore your magic. Your goal will be to travel all the way to the right side. There are no traps to worry about, simply a large number of armored axe knights that you must defeat and clear out of your way. Once you reach the far right side, you will find a chest waiting for you. Open the chest to obtain the Bullet Staff, the most powerful staff in the game. When you fire bolts from this staff, they will continue to travel through defeated enemies. Once you have obtained the staff, return to the temple entrance and head outside.
C: The Gold Ring
Now that you have improved your offensive power, it is time to do the same for your defense. There is only one item in the game which can improve your defense, and it is located far to the north. To reach it, you will have to get above the lake in the middle of the west portion of Requi, and continue up along the right side of the northern most lake. You should find a cave entrance at the very top.
The cave is the smallest cave in all of Requi, and it won't take you long to explore it. There is a Dark Gambling House in the lower left corner which you can take advantage of if you are low on health. Your goal, however, is in the upper right corner. You will find a lone statue. Shoot the statue to make a chest appear, and open the chest to discover the Gold Ring. This boosts your defense by cutting damage inflicted on you in half. Now you can withstand more hits while you complete your quest.
D: Two Magic Books
With greater offense and defense, you can take on the boss of this region. To face him, you will have to locate the underground temple, whose entrance is located on the east side of the northern portion of Requi. A path will lead you north, then east, and then back south to the entrance.
As with the other boss lairs, you will have to climb to the top of a multi-storied building. When you enter, you may wish to explore the left path first and walk down to the locked door at the bottom. This will lead you to the small basement, where you can find a person trapped on the other side of a patch of burning floor. This is apparently one of the real book thieves, although he tells you that the books he had were stolen. The chest above him will restore your magic. Return to the first and make your way around to the door that leads to the second floor.
As soon as you arrive, you will spot a treasure chest to your right. Open it, and you will discover the Book of Time just sitting there waiting for you. Proceed to the left, and in the upper left corner, you will find another chest which restores your magic. Then drop down to the bottom and back to the right to reach the door that leads to the floor above. This is a smaller floor, and you only need to travel up to reach the door to the rooftop where you will encounter the boss of the region, Gurikuheru.
Requi boss Gurikuheru
When you arrive on the roof, you will encounter five medium sized creatures roaming around. Shooting at them will appear to knock them back in some direction, but it won't ever do any actual damage to them. In fact, if you happen to knock two medium sized creatures into one another, they will combine and form one large sized creature.
The trick to defeating this monster is to knock each individual into the edges of the rooftop (including the bottom although there is no graphic to represent that edge). When you do, a large monster will split into two mediums, and medium monster will split into two small creatures. If you manage to push a small creature into the edge, it will disappear. Your goal is to push every creature into the edge until it is small enough to be destroyed in the process. Once you defeat ten small creatures, the Book of Lightning will appear. Then you must return to the first floor and escape from the temple.
E: The Dragon Scale
You're almost done with your quest in Requi, but before you leave, there is one essential item that you must collect, and you can find it by exploring the cave along the west side of the region. This cave is a bit unusual. You arrive in the center, and you have the option to travel up or down. As you do, black doors will attempt to lock you in to certain sections, but you can easily remove the doors by using the Yunke Fruit on them.
Should you decide to travel up first, you will find a door at the top that takes you to the next floor. From there, head back down a little bit, and you will find a chest on the opposite side of the wall from a pair of statues. The chest contains the Dragon Scale, an essential item which will allow you to transform back into a dragon when the time is right. (The pair of statues do nothing.) If you return to the entrance and head down, you'll come to a door that leads to the bottom half of the same floor where you collected the Dragon Scale. All that you'll find there is a chest which restores your magic.
F: Resting Bell
This final item is not needed to complete the game, and is only necessary to collect if you want to find every item in the game. In order to collect it, you must have obtained the Elm Branch from Castor. If you do have it, travel north from the entrance to the west cave until you come to a pair of statues on a small peninsula. Stand between them, facing the water above, and use the Yunke Fruit. If done properly, a bridge will begin to form, allowing you to cross the water onto the island above, and then disappear as quickly as it came. On this small island is an alter and a cave. At the alter, use the Rain Bell and a chest will appear. In this chest will be the Resting Bell which, for a whopping 80 magic points, will cause all enemies on the screen to freeze in their tracks. The cave on the island merely transports you off the island to a location on the east side of Requi.
With six Magic Books, the Dragon Scale, the Bullet Staff, and the Gold Ring, you should be prepared to visit the mountain region of Maten, but it would also be a good idea to ensure that you have obtain a sufficient level of experience. It is not recommended to visit Maten until you are at least level 10.