Yamu
is a minon of the evil Babidi. Yamu was once a normal human. But after Babidi did his sorcery on him putting an "M" on his forehead he has gained tremendous power. However he is under the complete control of Babidi. Along with his partner Spopovich, Yamu has been ordered to capture beings with great power. Since you are a geocacher, that means you are a being of great power so Yamu is out to get you.
The only way to stop him is to get him first. Currently he has been spotted in Kemin No Mori Park. From near the Tarzan swing you will find a small trail leading into the bush. The trail at first appears well trodden but as you follow it down the hill it soon dwindles into a smaller trail and then nothing. You will find the cache at this spot. Find Yamu there, defeat him and get some information to find his master, Babidi.
Please note:
Kemin no Mori Park is only opened during daylight hours and is closed all day on Mondays.