Maturing Bubbles

"Maturing Bubbles" is the seventh episode of the seventh season of The Powerpuff Girls, as well as the revival, and is the 143rd episode of the entire series overall. The episode of scheduled for April 15, 2019 on Cartoon Network.

The episode focuses on Bubbles becoming a teenager from a freak accident of the Aging Ray, the Professor's latest invention.

Plot
The Professor introduces his latest invention to the Girls: the Aging Ray. Testing it out on an apple, the Girls are amazed by what it does. Curious, Buttercup wants to try it out on something else, but the Professor says that after a single shot, it needs to recharge for 24 hours, much to Buttercup's dismay. On the following day, the Professor heads out, giving Buttercup time to go into the lab and use the Aging Ray. Unfortunately, Blossom catches her with it, leading them to fight over it. Blossom pulls it out of her hands, leading to accidentally pulling the trigger, ricocheting the blast around the lab. As Bubbles comes in, the blast hits her, aging her 11 years older at the age of 17. Worried, Blossom and Buttercup approach their sister, who simply has no memory of what happened as the effects of the ray have also effected her mind as well. In shock, Blossom is worried that they have aged her, although Buttercup sees the upside that having a teenage sister will be amazing as she thinks teenagers "are able to do stuff as adults do", in which Blossom dismisses.

Sneaking her into their room, they decide on whether or not tell the Professor about Bubbles, but when the Professor returns home the teenage Bubbles shouts out, "Hi, Daddy!", giving away their presence. She then flies down to greet him (as well as saying that she hasn't seen him in five years). In the lab, Blossom and Buttercup explain what had happened, much to his dismay. Buttercup gets ready to shoot Bubbles with the ray, but the Professor forgot about telling them that it only ages things forward, so he will have to make a reverse-Aging Ray to change her back, which could take a few days, much to Blossom's disappointment and Buttercup's elatement. The hotline rings, then Bubbles answers it in the same manner as in the cockroach incident. Blossom snatches the phone and the Mayor informs them that a giant octopus is attacking the city. She and Buttercup head downtown, whereas Bubbles doesn't follow them, but fortunately, the Professor forces her to. At downtown, they find the octopus (who appears to be the same one from "Octi Gone") who is about to destroy a sushi shop. When Blossom and Buttercup try to drag it away, Bubbles just takes selfies of the octopus rather than helping her sisters, leading to them losing to the octopus.

A day later, the Girls arrive at Pokey Oaks, where Bubbles flies over to hug Ms. Keane, referring to her as "Mom", much to Blossom and Buttercup's surprise and to the students and Ms. Keane's confusion. After Blossom explained, the Girls take their seats. During class, Bubbles barely pays attention and trash talks some of the lessons, which brings Ms. Keane to send her to timeout. Back at home, the Professor grounds Bubbles after having gotten a call from Ms. Keane about what happened. At dinner, Bubbles glares at the Professor while Buttercup agrees that she wasn't helpful yesterday, but still hopes for the better. At night, Bubbles takes up the whole bed and has Blossom and Buttercup sleep on the floor, as of "being the older sister". Throughout the next day, they suddenly get disgusted with the teenage Bubbles, as does the Professor. Fortunately, the Professor had finished the Reverse-Aging Ray last night, so they can change Bubbles back.

When Bubbles returns with some pizza, they explain to Bubbles that it is time to turn back to normal, which puts her in confusion, leading to Buttercup explaining to her that she was accidentally hit by the Aging Ray, turning her 17 years old. Before she would be hit by the ray, Bubbles asks for some time to think about it, in which the Professor agrees, then Bubbles heads into her room and closes the door. Hearing a whoosh, the Professor rushes into the Girls' room and realizes that Bubbles flew away, leading to Blossom and Buttercup to follow her. Having lost her, they concoct a plan to lure her to them. Later, Bubbles finds a chihuahua in the middle of the road that is about to get run over by a large semi truck, in which she rescues. She gets trapped in a net tossed by Blossom and Buttercup, in which the chihuahua rescue turned out to be a trap.

Returning back to the lab, the Girls hold Bubbles as the Professor blasts her with the ray, reverting her back to normal. Unfortunately, it suddenly aged down Blossom and Buttercup into infants, much to Bubbles' excitement and the Professor's shock; making him faint.

The episode ends with the narrator saying, "So once again, the day is saved! No thanks to Bubbles.", referring to the teenage Bubbles, who reacts as she thinks he insulted her.