You want to see your girlfriend from the other side of the wall.
Kick the tent next to the tree so you can reach the tree. Kick the tree to make some room and you’ll see the crane on the other side of the tree. Jump over the tree stump to get to the crane.
Kick the crane four times and your trousers will rip. Touch the crane and quickly jump to hook your snapped trousers on the crane. It’ll take you on top of the wall. Now you can lift Mei up as well. You need to convince her that you’re the one so walk to the flower bush on the right and face to the left (looking at Mei). Touch the flower and quickly kick it towards Mei. But then your romance is disturbed.
Talk to Mei and ask her for a distraction. She’ll take care of the guard and get the poker. Now that the guard is harmless, touch the guard to take his leg. Touch him three times more to completely dismantle him. When the horse walks away, you can return to Mei.
Game source: A copy of the game was found here on the internet.