In Haneda, Tokyo, next to Ootori, lies Sehegaga Academy. Dreamcast, Mega Drive, and Sega Saturn are students there. To get the credits they need to graduate, they have to go inside many SEGA games and complete tasks there. Their first task is to go inside Virtua Fighter...

Dreamcast, Mega Drive, and Saturn are students at Sehagaga Academy. They've come inside the world of Virtua Fighter, but to get the credit medals they need to graduate, they must win 100 fights in a row. Soon, the trio finds out that this isn't just any regular fight!

Dreamcast, Mega Drive, and Saturn thought graduating from Sehagaga Academy would be easy, but they're finding it a lot harder than they thought. When Mega Drive finds out the next game is "Space Channel 5", she gets very sad about her lack of skills on the dance floor.

Dreamcast, Saturn, and Mega Drive have come inside the world of Space Channel 5 to get the credits they need to graduate. They challenge aliens to dance battles with Ulala to save Center-sensei's friends. But not only do they have to save them, they have to earn viewer ratings too. Saturn strips down to her bathing suit to help earn ratings, but things take an unexpected twist thanks to Center-sensei's friends.

Dreamcast, Saturn, and Mega Drive must complete tasks to earn credit medals. But this time they don't have to go inside a game. Their task now is to use Puyo Puyo to create a new game. And anybody who comes up with a stupid idea will lose medals. Saturn and Mega Drive think hard, but Dreamcast is the first to raise her hand...

Center-sensei hosts an exam in which the girls must go into the world of the arcade robot shooter game, Border Break, where they can win a large amount of medals. Saturn, the only one who has to go on foot, is made into a decoy for the enemy, while Dreamcast struggles with her controls, leaving Mega Drive to take on most of the enemies. But as they're about to reach the core, suddenly, an Egg-shaped menace rears its ugly head!

Dreamcast, Saturn, and Mega Drive team up with Sonic the Hedgehog to chase after Dr. Eggman through various dimensional warp zones, briefly passing through his Genesis debut and his first 3D adventure, Sonic Adventure. Can the girls crack that egg-head wide open and stop the hacking for good?

With Sehagaga Academy's dubiously named culture festival arriving, the girls try to come up with an exhibit to show before taking a look at their competition for a beauty contest; chief among them being other SEGA Hard Girls, and an old flame of Saturn...

The girls are sent into the world of the mobile RPG Chain Chronicle, despite Mega Drive's dislike of mobile gaming. Can our three heroines succeed at their perilous journey and gain 15 medals before Center-sensei's phone battery dies?

With their next lesson taking place in the world of Jet Set Radio, the girls give Mega Drive her first sticker photo booth experience before working towards performing an awesome skate trick and having a race to reach the goal first. Who will claim victory? Place your bets now, ladies and gentlemen!

The girls' next lesson has them enter the world of Shining Force: Cross Exlesia Zenith... but dressed up as the Rappies from Phantasy Star Online 2. Can the trio overcome a mighty dragon that awaits them? Not if a real Rappy gets to it first!

Just as Dreamcast, Saturn, and Mega Drive are finally about to graduate, Sehagaga's network gets taken over by... a Center-sensei lookalike?! Now with almost all their medals taken, Black Asobin challenges the trio to conquer his tower and face him head on, in order to get them back! Welcome to his Fantasy Zone... GET READY!

The day has finally arrived, as we approach Dreamcast, SEGA Saturn and Mega Drive's graduation from Sehagaga Academy. But what does it mean for them to graduate?