1. Brother Love

Akiko moves into a school dormitory with her brother Akito, when he transfers to her school. Owing to her brother complex, Akiko has a crush on Akito. With both of them in student government, will Akiko be able to share him with the other council members?

2. Indecent

Akito catches Akiko reading a trashy romance novel. Akito, having trouble settling in to in his class, is given firsthand lessons in the concept of "tsundere"from both Akiko and Anastasia. Akito and his longtime friend Ginbe get into an argument.

3. No Bra

Akiko asks Akito for help changing her light. Akito has his hands full maintaining the dorm, from fixing the plumbing to repairing the doors. The girls have differing opinions over allowing Akito to take in the laundry. Akito helps Anastasia settle in.

4. Naked

Akito brings home a special dessert, just for Ginbe to enjoy. Akito continues to fix up Anastasia's room, and the two of them discuss her hobby of collecting stuffed animals. Arashi has the girls take a bath together, to help them bond together better.

5. Sexual desires

In a student government meeting, the council members discuss what they are going to call Akito. Kaoruko proposes that Akito write a short story to be published in a women's magazine. She grows concerned for him when she learns his sibling is a sister.

7. Chippai

Akiko is upset over not being consulted before Arisa, who claims to be Akito's fiancée, was hired as dorm manager. Later that day, Arashi proposes that Akiko and Arisa compete in a contest, to see which one of them is the better little sister to Akito.

8. Colorful

The girls all go to find new swimsuits even though summer is still in the distance. They try frilly ones, sexy ones, and cute ones. Then, Arashi proposes a contest to show of their new goods and Akito must decide which one impresses him the most.

9. Nii-Nii

Akito follows Gin to the back of the school building to find out why she is acting so suspiciously. When Akito suddenly falls sick, everyone fights over who will nurse him back to health. They decide to take turns treating him how they see fit.

10. “Gindama”

During her turn nursing, Ginbe reminisces about Akito's transfer to her school and how they first met. After Akito recovers he has to choose the winner of the contest he had no idea about. What is the prize and what will the winner do with such a chance?!

11. Ephemeral

Unable to find her panties, Anastasia decides to go commando for the rest of the day. Arisa gets frightened by something she sees outside of the dorm and the group decides to investigate the source. All the while, Kaoruko sleeps in a feverish slumber.

12. It's love

Everyone gets separated and Akiko is left alone with Nasuhara. While contemplating her panty dilemma, Nasuhara reminisces about her first meeting with Akiko. What will happen to Akito and his crew of crazy girls that sleep under the same roof?