Budi and Rosi are assigned by the teacher to raise the flag on Mondays. But when the teacher gives Budi the flag for washing, he falls asleep and forgets that the bucket he is using to soak the flag, is usually used by his neighbour, Bang Ali, to wash his bajaj (motor tricycle). Budi panics when he learns that the flag is missing. He calls Rosie and they look for it around the house. Then Bang Ali returns the bucket, and they rediscover the flag. But when they wash and dry it, the flag goes "missing" again. This takes Budi and Rosi on an "adventure" to find the flag again.