Actually, I wasn't sure whether I should make a walkthrough for this game since the game is kinda straightforward, but I decided to make it anyway to list people that give you items when you talk to them.

I won't cover things in detail. I might tell you if there's an important chest containing Project items, which can be crafted for tier 3 weapons and/or armors, but I won't tell you every item that you can pick up because 1) most of them are plants, and 2) it'll ruin exploration. Plus, there are some hidden chests that I missed and the game tends to reset whatever items you have when you change party members so it's kinda useless to collect everything.

• Press and hold action button (Z or space) to speed up dialogues and walking speed on cutscenes
  
• Enemies will only give you gold, not exp, so feel free to avoid them if you want. It's still easier to clear them to find chests though, but it might be harder to do in any difficulty except Relax.
  
• Although the game says that Story difficulty is easy, it's not. It's normal mode.
  
• Make sure you change your weapons (and armor if you want, but I never bother with it since I played in Relax difficulty) to the effective ones for every enemy.

Fruit and flower names:

Lastly, here are all parchments that list helpful info in the game if you need it.

Party: Banks

Follow the tutorial until you reach part 1.

Party: Aris, Enkas

Talk to the woman near the stair to get Sapphire ring. Head upstairs and talk to the guy behind the candles and dragon pillars to the west to get Strong poultice. Talk to the guy that is blocking the door to the north to get a Letter. Head downstairs and inspect the woman portrait on the northwest corner (the bed area) to get a Pass. Return upstairs and give it to the guard in the northeast corner.

Follow the tutorial and land on the first island you see. You need to gather enough planks to continue the journey if you somehow damaged your ship. Don't forget to open the treasure chest to get a weapon. You can head west when you see an enemy on the west area after you fly your ship again to reach a hidden and optional island. Make sure you go there through the path with less clouds since you'll just get bounced back otherwise.

Follow the path and do the same on the next island and pay a tribute to the Gods. Keep on doing what you did for the next few islands. The ship might be hard to control when the storm comes in, but it's still doable. Remember the pattern and avoid hitting anything. Continue the path until you reach Sky Watcher Base. There's a boss waiting at the end of the road.

Party: Sen, Laika, Kei + Amercia

There's a slight stealth section at the orphanage area. Once you cleared it, speak to the orphanage lady and exit the room. Follow the path until you reach a building with pig farm and talk to the person in front of the building to get Adamantine ring. Talk to the guy with the ragged clothes in front of her to get Ruby ring. Follow the path again until you reach 2 stairs that lead to the same area and talk to the woman in front of the nearby house to get Strong poultice. Continue onward until your party changed.

Party: Amercia, Jandar, Guard

You can buy any supplies that you need before proceeding. You might need to learn some skills beforehand too. Flurry of blows is a good attacking skill if you have the tome that can be found in the area after you exit the village.

If you head to the inn, there are some bounties that you can take for a reward. Project: Claymore can be used to create a Lv 3 sword, which is the best sword in the game. You need to save up 900 Gald to craft 3 for your party after you cleared the bounty. The mountain bandits are located to the north after you exit the village, in the place where you find 4 wood-shaped barriers(?). It might look like it's not passable, but you just need to head north to reach the bandits.

Follow the path to the east afterward until you find a chest containing Medium and bridge crank and return to the campfire near the town's exit. Now, follow the south path until you find an area with 5 wasps. Inspect the wooden structure with the hole near the bridge to lower it.

The next bounty boss is near this campfire. Head a bit to the north, than southwest when it allows you to and follow the path. The boss is weak to medium attacks. The last bounty is located northwest from the campfire. It shouldn't be hard to miss. If you see another wood-shaped barriers(?), they're there. The rest of the path should be straightforward. Follow the path until you reach another village.

Talk to the white-haired man on the way to the south to get Powerful potion. Explore this area for enemies and flowers if you want and head inside the inn to pay 10 Gald to rest when you're done. Also, I know the game is telling you about bounties, but we already cleared them; you don't have to bother with it.

Party: Aris, Zayne

Back to the airship driving minigame. You know what to do. Drive the ship to an island, stock supplies, repeat. Explore everything on the island too. You might want to buy some Lv 2 weapons before proceeding. You need light and heavy weapons, with light weapons being a priority. Note that Aris already has Tempered sword equipped so you don't need to buy a lot of them. However, you can get an extra dagger and mace if you keep on going the difficult course later, so it's your choice.

The path will split up at some point. Feel free to choose any route that you want. Both are fine too. If you didn't buy any weapon before, I suggest you to use the difficult course. I found the fights in easy course to be harder later on and had to ditch the course completely. You only need to fight once if you do so, make sure you start with light weapons.

Party: Zayne, Aris (you still retain the equipment from the previous voyage)

Head north until you reach an inn and head southeast until you find a stair hidden behind the houses. Speak to the man near the sign to get Silver ring. Head a bit to the north and then east on the next intersection to find a lady. Speak to her to get Gold ring. Enter the inn for a cutscene.

Party: Zayne

Exit the room and talk to the lady near the inn's exit to proceed the story.

Head to the northwest exit and enter the buildings marked on the map. Inspect the note inside the first building (the last house before the second stairs). Exit the house, head upstairs, and talk to the elven guy near the house with green carpet to get Powerful potion. Head inside the second building (the house with brown carpet). Inspect the note in this floor and upstairs, and head downstairs afterward. Inspect the note and the bookshelf next to the wall. A secret path will be revealed. Inspect the note and return to Aris by the inn.

Party: Sen, Laika, Kei

There's a bit of stealth section before you leave the city. Sometimes it's annoying because the guards placed so close to your path, but what can you do? You need to wait for the guard that has "..." balloon on him to fall asleep before proceeding. As for the way before the bridge, you need to circle the house to pass the guard.

Strangely, the fight section is the easiest of what you'll experienced. Everyone will be healed after every fight and enemies don't hit that hard. The path shouldn't be hard to traverse. Just keep on going until you reach the sewer.

Party: Amercia, Jandar, Guard

Head inside the inn to check for new bounties. Stock up and head south from the village when you're ready. Stick on the southwest path until you see a carnivorous plant to finish your first bounty. If you're wondering, their weakness are medium weapons. Head back to the village and craft your new weapon if you want.

Follow the path to the southeast from the village until you meet a guard that says that the road is closed. From there, head north to find another bandit camp. That's your second bounty. Head back to the village and craft the armor if you need.

The last bounty is located quite far from these two, so let's leave it aside from now. Keep on heading south from the village (doesn't matter which path you take as long as you're not going to the path to the second bounty), and keep on moving south on the next screen. Stick to the southwest area when you find a campfire. You'll find a camp with a pentagram to learn a skill. Head to the southwest again to find horde of monsters and a chest containing Project: Masterwork medium. Talk to the guard on the southwest area to learn a skill. If the first campfire that you find is located in the next screen, head northwest instead to find the camp with the pentagram.

Head to the campfire to reach another village. The next path might look like it's split into three paths, but they lead to the same screen. If you head to the westernmost area in the next screen, you'll find a campfire. Talk to the guard to learn a skill. Now, head to the easternmost area and keep on heading south for your last bounty with 8 enemies. Follow the path and head northeast on the next intersection afterward to find a chest containing Project: War mallet. Head south to the next screen.

The chest near the mines entrance contains Project: Masterwork magic. The rest of the path shouldn't be too hard to traverse. You'll have a boss fight with a lot of enemies at the end of the area. You'll have a choice to fight either 8 or 6 enemies. If you choose the latter one, you will lose a party member later on. It doesn't matter though since you won't play with these party members anymore until the game ends. Tips: Blizzard + Spin attack combo does well to wipe out the front row.

Party: Aris, Zayne, Rays

Head to the dock through the southeast exit. Follow the path until you catch the guy. You'll have a tough boss fight at the end.

Party: Sen, Kei, Laika

Follow the path until you exit the sewer. There will be a short stealth session afterward where you have to go to the other side of the gate to open it. The rest of the path should be straightforward. There will also be a boss fight at the end.

Party: Zayne

Consult your notes if needed. Choose these options whenever you have several options to choose from:
Meh, I'm very sleepy (the other options are also fine but they will treat you as a rookie afterward)
Flying bear
Take a bottle of red wine
300 Gald
In the northen skies
Let me guess, another woman is involved? (the other options are also fine but this one doesn't raise suspicions)

There will be several tough boss fights after the cutscene ends. Try to hold out until backup arrives. Kill everyone afterward. Tips: Make sure your party doesn't move to the backline when the enemy said to take care of the ones over there. The fight will end after you finished the boss with the heavy armor and there will be a separate fight with him afterward. You'll be recovered to full health after every battle, so don't worry about it.

Congrats for beating the game!

I was planning to give tips for every boss but I don't think it'll be that helpful since I played in the easiest difficulty. I give several tips that I found useful for some fights though. Not sure whether it'll work in the harder difficulty but at least you get some tips. Anyway, good luck with beating the game!