The Campaign is where all players start, and initially the main source of Academy Experience.
There are no restrictions on the number of times the stages of this mode can be played, the only limiting factor being the player's stamina, displayed at the top right corner.
Battling through the Campaign rewards players with gears, gear dots and experience juices.
The Normal mode of Campaign has a story about a boy that found a box, left by his father who disappeared, which contained a broken card. It can be very confusing at times, mostly due to the poor translation of the game's original version, 我的學妹不可能那麼萌. You can check out a summary of the story, up to Chapter 10, down below.
From this point on, beware of spoilers!
The main character starts a new school year with Rocky belittling him, Jacky admiring him and learning the existence of Nathan, a strong Battle Girl summoner. He learns from Nathan that the broken card can be fixed by someone named Norson for a million dollars.
He plans to enter the Championship along with Nathan's little sister named Yuki and a girl he met named Rene for the grand prize which is a million dollars. Rocky kept bothering the three so that they don't make it in time for the registrations, but they barely made it in time. After winning, Rene and a man named Jacob take the prize money, betraying the two and taking Nathan away, but he is rescued in the end, along with taking back the prize money. Nathan has lost his power to fight, though.
The boy then goes to Norson who said that the broken card is a legendary Battle Girl named Kratos. After the boy muttered on where his father might be, Norson hinted he knew where the boy's father was. When the boy pressed him about it, the man avoided the subject and left.
The boy wants to find Rene and Jacob, but Yuki is against it. Jacky, who just got out of the hospital, kept complaining about how hungry he was, but they ignored him. They run into a man who they believe to be one of Rene's allies. The boy fights him, and throws the man unconscious. They bring him to the hospital.
They encounter Rene next, who was looking for them because she wants their help. Yuki doesn't believe her and believes that she is trying to bait them into a trap, getting ready to fight to avenge her brother. Rene then says that she can help Nathan restore his powers and that she was just following orders from her organization. The main character has a good feeling about this so they decide to follow Rene. Rene encounters Rocky on the way, who was harassing her, and Rene was about to fight him when the boy defeats Rocky himself, saying that only he can defeat Rocky. Rene jokes about him having a crush on Rocky.
Rene leads them to where Jacob is, waiting for their arrival. Jacob challenged the boy but lost, muttering a certain man's methods were too slow. The boy then sees his father, who he hasn't seen in years. His father says that he grew up a lot and fixed the card that he left the boy with. The boy asks for an explanation as to why he disappeared so suddenly one day. His father explains that when the corruption started on the higher levels of the school management, called the Union, he tried to fight them and that Rene and Jacob are his disciples, and the destined future leaders.
The boy, after the revelation, is left shocked, to the point that he is unable to answer Jacob's questions. His dad says to go and rest for a while and that he has other matters to attend to so he's leaving. Jacob and the boy meet up with Rene, who was starting to worry because they were taking so long. Enemies from the Union arrive and they plan to flee. The boy says to look for Nathan, who might be in danger since he hasn't restored his powers yet and unable to communicate with his Battle Girls. They conclude that they should go to Norson for help in the meantime.
Jacob leads them to the place where Norson should be, but he is nowhere to be found. Jacob assumes that he has been kidnapped by the School Union already, the enemies that went after them were probably just a distraction. They then went to where Yuki and Nathan were, waiting for the boy, only to see him with Jacob and Rene. Yuki prepares to attack Jacob, attempting to avenge her brother. The boy stops her, saying that they're not as bad as they seemed to be, despite them harming Jacky and Nathan during the Championship in the past, and that they were doing it for a good reason. He explains the current situation to the siblings, leaving Nathan confused as to why would Norson be kidnapped by the School Union.
Attacked by the Union, they find out that it has taken over the school completely and that the materials for making Battle Girls stronger are in their hands. Jacob says that he knows a secret passage that they can pass through to get away from the enemies and obtain the materials. The main character stays behind to distract the enemies, along with his father. After a while, his father said to go and leave the rest to him. A mystery man appears before the two and claims that he's not letting Merlot, the main character's father, escape this time around. The main character hesitates to leave, but his father says that leaving him is the best help that he can get.
The main character catches up with his friends and they found the materials. Jacob activates the materials but he says that you need to train to improve them. The main character then says that training is not an option right now and prepares to fight against the Union. Rene tries to hold him up, saying that it's too dangerous to use them if he hasn't trained, but still, the main character fought. He had difficulty in using the materials, but he was able to manage. Jacob says that the main character can improve his cards using the materials if he has enough control over them.