hi, i've been looking and scanned all gameboy roms possible still can't find the RPG that i've played during my childhood years. It is japanese, so i don't know the title, but I managed to finish it.
Now im searching all over the net for it.. hope anyone can help me. since I don't know the title, I'll just described the gameplay and plot.. hopefully someone might know this

It's a 1 character RPG, at the beginning there's 2 guys fighting. then the other guy left with his troops on a boat. the hero also rode a boat and went to a different place. at town there was an earthquake, then you head to the castle at the center to open the bridge going right. you buy a saw, and use it to fight a tree monster, then you met a witch and give you the ability to turn into a frog.. Now the fighting is not hack and slash, you just bump the enemy and a smoke-like censored for violence will appear, then your heart and enemy heart starts to get damage each turn..
If someone knows this RPG please pm me the title.. its japanese, and till now Im still searching for it.

PS. the final boss is a serpent on top of the castle, and the witch will become a princess..XD