Mikagura School Suite

As Eruna Ichinomiya, a somewhat perverted schoolgirl, is pressured into choosing a high school, her cousin, Shigure Ninomiya, recommends his school, Mikagura Private Academy. Taking an interest in the principal's granddaughter, Seisa Mikagura, Eruna decides to take the entrance exam, which she passes by being able to see the school's feline teacher, who she names Bimii. At the start of her new school life, Eruna learns about the school's system, in which students are required to join one of the school's clubs, using points earned by battles against other clubs to improve their state of living. Stuck with the poorest living conditions due to not yet being in a club, Eruna attempts to join Himi Yasaka's Calligraphy Club, but is rejected due to her poor art skills. A few days later, however, Eruna is approached by Seisa herself, who invites her to join her Going-Home Club on a trial period on the condition that she act as the club's representative in a battle taking place the next week.

After learning about how students can use special abilities during club battles, in which student's must destroy all three of their opponent's crystals, Eruna pays a visit to each of the different clubs, learning about the various abilities the representatives have. However, Eruna struggles to come up with her own special ability by the time of her match, in which she must battle against Himi. As Eruna quickly finds herself on the defensive and goes into hiding, she comes across a sealed room and briefly sees a mysterious woman, who tells her that she has already possesses a power inside her. When she regains her senses, Eruna discovers she now possesses super speed and a finger laser ability called "Toy Gun", which she uses to destroy all of Himi's crystals in one go and win the match.

After learning about an upcoming rookie tournament for new students, Eruna reports her victory to Seisa, who claims that she only won because Himi held back and challenges her to a practise match with her club membership on the line. Prior to her match against Seisa, Eruna observes a practise match between the Astronomy Club's Asuhi Imizu and the Drama Club's Yūto Akama, with Yūto winning with a single strike. The match between Eruna and Seisa soon begins, with Eruna attempting to destroy Seisa's crystals whilst she is dozing off. However, Eruna's Toy Gun fails to activate and she is overwhelmed by Seisa's "Killing Art" ability, getting kicked out of the Going-Home Club as a result. Bimii, after informing Eruna that she needs to build more experience to use her ability properly, suggests that she form a club of her own, using the rookie tournament to attract potential members. Admiring her determination, Seisa lets Eruna bring her sleeping bag into her mansion.

With Eruna still struggling to use her Toy Gun properly, the Drama Club decide to put on an after-school beginner's class in the run up to the rookie tournament. As Eruna learns she will be facing against the Calligraphy Club's Meika Katai in her first rookie match, Yūto is feeling down as Asuhi reminds him of his younger brother, who was separated from him when their parents divorced, leaving him all alone. However, he is cheered up when Eruna and the other Drama Club members hold a party to mark the end of the beginner class. The next day, as Eruna faces off against Katai, her excitement from enjoying the duel allows to once again use her Toy Gun and win the match.

Eruna and Seisa take a look around the tournament's festival, where they end up standing in for Flower Arrangement Club's Sadamatsu Minatogawa, who is running a shooting gallery with his prized life-size Super Miracle Man doll up for grabs. After both Yūto and Eruna fail to even budge the doll, due to Sadamatsu protecting it with his ability, Seisa knocks down his second-best prize, which attracts more attention to the booth. Later, as Eruna hangs out with the Drama Club's Usamaru and Tonkyun, Seisa meets up with the Art Club's Kyōma Kuzuryū, who observes how she has changed since meeting Eruna. After Eruna clears the second round in the tournament, she witnesses Usamaru being overwhelmed by the school band's Azumi Sagara, who can manipulate gravity with her music, her victory prompting a harsh reaction from Seisa.

After holding a pep rally for Eruna, Shigure tells her about how he and Kyōma transferred to Mikagura from another school, which revolved around sports clubs, where Kyōma became distrustful of other people. As Eruna proceeds further in the rookie tournament, Tonkyun goes up against Azumi, managing to trick her into coming up close so that he can take advantage of her ability's weakness and win the match. This leads to Eruna and Tonkyun facing against each other in the fifth round, where Eruna announces her plans for a "Surrounding Eruna Ichinomiya with Cute Girls Club". As the two clash, Eruna brings out a new ability, Toy Bayonet, to win the match, igniting Kyōma's love of painting once more. After Eruna is inevitably eliminated in the quarter-finals, the tournament is won by a girl named Otone Fujishiro, who defeats Asuhi in the final round.