Well, you must finish the 4-Season-Island quest in order to "change his mind". To unlock the 4-Season-Island quest, you have to go with Blue into the Aura Cave and meet the guy with the Onix. There is however, another condition. There are 2 NPCs (both of them old ladies) who talk about the Nevarone legend. You must speak to both of them, first with the first one, then with the second one. After you've heard the legend of Nevarone, then the quest will be unlocked.
Now, I'm sure one of the old ladies is in Nostram City. The other one... I'm not sure, my brain's not working very well right now, I've been working 15 hours per day for the last few days. The answer should be somewhere in the forum. Or you can try to find her yourself. Try the first few cities.
Once you've heard the legend, go to the 4-Season-Island, and there should be an old man. He will give you a handful of quests, and once you've completed them all, the 4-Season-Island quest will be complete. Then you can finally go to the Sea of Bodom. Have fun :)
Now, I'm sure one of the old ladies is in Nostram City. The other one... I'm not sure, my brain's not working very well right now, I've been working 15 hours per day for the last few days. The answer should be somewhere in the forum. Or you can try to find her yourself. Try the first few cities.
Once you've heard the legend, go to the 4-Season-Island, and there should be an old man. He will give you a handful of quests, and once you've completed them all, the 4-Season-Island quest will be complete. Then you can finally go to the Sea of Bodom. Have fun :)