Monkey King wanted to borrow the fan from Iron Fan Princess
The monk Tripitaka and his disciples, escorted by the Monkey King, are on their way over the Himalayas to India to take back the Buddhist scriptures when they are blocked by the Flaming Mountain, an impassable mountain range. The Monkey King realizes that the only way through is to borrow the indestructible magic fan from the Iron Fan Princess. The Princess, however, angry with the Monkey King for having sent her son to be a disciple of the Goddess of Mercy, refuses to lend him the fan.
A fight between them breaks out. Failing to snatch the magic fan, the Monkey King, master of a thousand transformations, turns himself into a bird. When the Iron Fan Princess drinks from a cup, the Monkey King leaps into the cup and is swallowed. Tumbling inside her and causing terrible stomach pains, monkey forces the Princess to relent and lend him the fan.