A year after the Sky Girls defeated the WORMs, an unknown threat was building up in the Artic that would threaten the world again.
"It took just one year, but now the new WORMs shall rise," said a female voice from one of five single cells that were floating in the sky. Meanwhile, at the army base, the Sky Girls were getting together for the anniversary of the defeat of the WORMs.
"Can't believe it's only been a year," said Otoha as she got out of a taxi at the front gate. She was dressed in a formal military uniform.
"It's about time you get here, Otoha," said Eika who was also wearing a formal uniform.
"Sorry, my boat was late getting in, has everyone else already arrived?" asked Otoha as the driver got her luggage out of the trunk.
"Everyone's in the hanger," said Eika with a smile.
"Then let's go," said Otoha after grabbing her bag which had her wooden sword sticking out of it. A few minutes later, the two walked up to an open hanger.
"Thanks for helping me with setting the tables, Karen," said Takumi.
"It was no big deal," said Karen whose face was bright red.
"Looks like you two have gotten closer," said Otoha while standing behind them with Eika.
"You made it," said Karen as she and Takumi turned around to welcome her.
"Nice to see you again, Otoha," said Togo as he approached them along with Aisha and Elise.
"It sure has been a while," said Aisha with a kind smile.
"I'm glad to see that you're ok, Aisha," said Otoha who was also smiling.
"Thank you," said Aisha.
"Oh, before I forget, I found this in my office for you," said Togo as he handed a letter to Otoha.
"Who would send me a letter using paper?" asked a confused Otoha. When she opened the envelope, she read out loud, 'Dear Sky Girls, I know you think the fight is over, but I know something about the WORMs that you don't, if you wish to find out what it is that I know, then come to the museum where your Sonic Divers are'.
"I don't like the sound of that," said Takumi. Later, at the museum, the five girls and Togo were standing in front of the Sonic Divers.
"It's great to see you again, Zero," said Otoha as she looked at her old partner.
"Good to see that you got my letter," said a guy with red hair and green eyes as he came out from behind the Sonic Divers.
"Who are you?" asked Eika.
"My name is Mimizu (Earthworm) Kuchiku-kan (Destroyer), and I'm a WORM HM," said the boy as his right arm turned into a tentacle, surprising everyone.