Yie Ar Kung Fu 2: Yie-Gah Koutei no Gyakushuu

At the title screen, press "E" 1 time, "S" 2 times, "C" 3 times and "F" 4 times. If done right, the game will auto start.

Insert Yie Ar Kung Fu 1 in the 2nd cartridge slot of the MSX while Yie Ar Kung Fu 2 is inserted in the 1st cartridge slot. Now, after level 2, if your energy (and the enemy's) is in the red and you have less energy than the enemy, your father will appear and give you a cup of tea that fills your energy.