With the ogre, you just have to have your creature beat him in battle.
Your priority though should be in converting the Japanese town nearby. Once they join you, you can click on a scroll which involves you playing a tune on a series of bells to get rid of the shields around the "thing" ( I can't even remember what the bleddy thing is called).
If memory serves, the lonely man is on top of the same hill the Guide was on Land 1. If you want to bring back keiko to him, you have to take over the Aztec village on the far end of the island. I believe she's there.