You can head back to the Town Hall to find Sue, and she will explain her desire to fix the teleporter system on the island. In order to do so, she needs special data cards from the teleporters she'll connect to.
The closest one, and next destination, is in Grasstown. Head to the Reservoir to the left of the village and use the newly opened valve to reach the door on the left.
Grasstown - Opening Area
Head to the large building on the right, and go inside. A Mimiga named Jack will greet you and reiterate Sue's request for a data card, and an idea on where to look for it. To head deeper into Grasstown, climb the building and leave through the topmost door.
Once outside, climb up some more and head to the left. Examine the console to turn on some fans in the opening area, and head back to the right to reach a small building. As you approach, something inside will hiss...
Someone, or something, seems to be messing with the teleporter. If you approach them, or try to leave, they will notice you and try to attack after a short conversation.
Suto will jump very high into the air, and try to land on you. After landing, he'll shoot three balls of energy towards you, then repeat the pattern.
The strategy for this fight:
After the fight, head back to the building below and speak with Jack again. He will ask you to head to an old storehouse on the far side of Grasstown, and gives you a key to the Generator Room, a medium-sized building to the right of the Teleporter Room.
After unlocking the door, examine the large computer on the right to turn one some additional fans next to the Teleporter Room. You will need to go back this way to reach an auxiliary power console above the Generator Room.
Grasstown - Closing Area
After turning the auxiliary power on, head to the right to a series of pillars. Under each pillar is a console that will turn the fans on on its respective pillar, as well as the horizontal fans above it.
The sixth pillar's terminal is actually on a block half-way up it, and requires climbing the previous pillars to reach it. There's also a pesky ventilation fan on the top right that prevents you from reaching the Old Storehouse...
The solution is as follows:
Open the chest...
BOSS: Suto (#2)
Suto will flutter across the room before landing, and causes several bouncing balls to spawn upon doing so. These can be shot and broken to produce EXP or heath, but will take an increasing number of hits to do so if your weapons level down.
After landing, Suto will shoot three balls of energy like he did before, and then leap across the room again. There are also some fans on either side of the building's ceiling that will push you around if you try to jump over his projectiles.
The strategy for this fight:
After his health gets low, Suto will stop fluttering mid-jump, and instead land immediately, causing a much higher volume of bouncing projectiles. He also won't clear the entire room in a single jump, so use the extra space between you to your advantage.
After the battle ends, you're free to leave the room. Once you leave, however, an earthquake rips the floor right out from under you! You'll fall helplessly down to a new area, The Underside.