Guide to Walkthrough
Chapter 1 - Getting Started & Courier Forest
Grab Saya's amulet from your house and pick the flower from the field next to your house, after this head north to Saya's mothers grave site. You'll be abducted and taken to a lockup on a boat, stealth past the guards and you'll wind up on the west continent.
After talking with the doctor who saves you, head to the middle east section of town to meet Musshu, you can sell treasures you find from dungeons and monsters here.
Next, head to the guild which is near the middle of town, directly west of Musshu's building. You'll receive your first request from the guild, to get herbs from Courier Forest in the north.
You'll encounter Slime enemies here. They have about 200 hp and can be taken out with 1-2 tier 1 ice spells. I recommend fighting all the ones you see, there's a magic circle before the boss that will regenerate your health and mana to full, so don't be stingy with your mana. Once you reach level 4 and acquire the 2nd tier ice spell, you should be able to beat the boss here with relative ease. Upon defeating the boss, you'll receive Shining Golden Grass, return to the guild for your reward.
Chapter 2 - West Mountain
After resting from the day prior, you'll go to the guild to receive your next task, picking up a Eubird's egg from the west mountain. Before heading out, sell your treasures with Musshu and pick up a Guardy Remastered from the general store (to the left of Musshu's building). This item will significantly improve your ability to absorb damage.
Leave town from the east or west exits and you'll be on the overworld map. Head directly west to the mountains and you'll be at the west mountain location.
There are 2 enemies here and a boss, Goblins and Hydras, I recommend grinding to level 8 here upon which you'll receive a new spell called Freezing Breath. This spell hits all enemies and causes the blind debuff at a high rate. It'll be important for minimizing boss damage going forward. Work your way through the mountain and cave that comes after and save at the recovery circle. Head east from the circle for a boss fight. Between the Guardy Remastered and keeping blind up on the pair of bosses here your damage taken will be fairly low, keep watching your health and heal when you need to. If blind is up on both bosses you can start using your highest single target ice spell. Upon beating the pair of bosses, go to the backroom, grab the treasure, and head back to the guild for your reward.
Chapter 3 - Volfophia Volcano
Head to the guild and you'll receive notice about some activity at the volcano north of town. Before leaving town make sure you purchase the Eternal Ice item from the general store. This will allow Saya to fight the upcoming boss significantly better.
You'll encounter two enemies here, Trolls and Hell Beasts. Head to the east to pick up a pickax which will allow you to proceed to the bosses lair. Once you reach the magic circle, save and break the rocks next to it. I recommend having your third tier ice spell and your second tier recovery spell before proceeding, level 12-13 should do. Make sure to equip the Eternal Ice before proceeding. The boss strategy is the same as the prior boss, keep blind up on it and pelt away with your strongest ice spell. Keep your health high as the boss periodically casts a fire explosion which will deal pretty significant damage to you.
After beating the boss Saya will retreat and return home. Upon gaining control of Saya again you can head back to the bosses lair and pickup the treasure chest there. After this, head to the guild for your next task.
Chapter 4 - Investigate the Iomu Ruins
The guild will ask you to head to the ruins for your next task, this is slightly south west of town on the overworld map. If you have the money, buy a Holy Twig from the general store. It will make the next boss slightly easier. For now, you can return to using Guardy Remastered to reduce your damage taken.
The Iomu ruins also have two enemies you'll face, Undead and Squid. Start heading south to reach the magic circle, defeat as many enemies as you can along the way to keep grinding higher levels. Upon reaching the magic circle, head to the door slightly to the right and equip your Holy Twig if you purchased it. I recommend being about level 16 for this boss fight. Treat this boss fight the same as you have the others. Keep blind up and use your strongest single target ice spell. Heal as necessary. This boss also has a magical blast which deals a fair bit of health, so try to never fall below 50% to be safe. Upon defeat the boss will drop a key to the treasure room and "boldness" which will open up monster lairs to grind in. You may have noticed them in the prior dungeons, they're areas will large quantities of monsters in small areas.
Head north to the treasure room and then you can leave the Iomu Ruins. After exiting the ruins you will receive your reward.
Chapter 5 - Voreworms & Ending
The next day you'll receive a request to head back to the Courier Forest to defeat Voreworms. This is essentially just used to acquire the money to head home if you haven't already acquired 30,000 in your savings.
Courier Forest & Voreworms
Head to the forest and look for the large green tentacle like creatures. These hit pretty hard so I recommend reequipping the Guardy Remastered. Upon defeating the four of them, return to the guild and hand in the tentacles they dropped.
By this point you should have enough Dell to buy a ticket and head home. Head to the port and purchase a ticket from the Sailor nearest the middle dock. This will lead you to the normal ending, which is the only ending in the PG13 version of the game.