Something's a Miss is the 17a episode of the season 1.
It all begins with Flapjack watching some rich people have dinner. They spot K'nuckles in a soup bowl and he gets kicked out. They soon head on over to the girl's club. K'nuckles did good but they also kick him out(no boys are allowed). Soon Flapjack walks in and says hi to the girls.But they think he's a girl! Flapjack tries everything to be a boy. But there was only one thing to do this, Surgery! Meanwhile, Bubbie wonders where Flapjack is. K'nuckles tells her he went to Doctor Barber's for some Surgery. It wasn't too late, but Flapjack has a girl's voice now. Doctor Barber tells him that he got tired of your boy's voice and added in a girl's. The next morning, Flapjack's back to normal and the girls tell him he is not allowed anymore.
We learn that Stormalong Harbor has a girl's club.
You can hear music playing from the Spongebob Squarepants Episode "Boating School".
Goof: When K'nuckles was talking to Bubbie, it was nighttime, but when K'nuckles went to see Dr.Barber it was daytime.
Goof: The door was open when K'nuckles barged in to see Flapjack, but in the next scene the door was closed.