Season 4

Yumi and the Yamayurikai prepare a production (The Tale of Torikaebaya) for the upcoming school festival with neighboring boys school, Hanadera.

The day of the School Festival has arrived, there are many attractions but most importantly, the drama club is performing Little Women and Yamayurikai, The Tale of Torikaeba. With so much going on, the day might not just be another ordinary day.

This year's remaining, petite soeur-less en boutons, Yoshino and Yumi are feeling the pressure to find their little sisters, for various reasons. Yoshino suggests that they have a Soeur Audition to do just the thing.

The day of the Soeur Audition—turned into Tea Party—arrives, and soon the Kendo Competition, as well. Yoshino has been looking forward to the Kendo competition, but she has promised Eriko that she will have a petite soeur by then. Someone catches Yoshino's eye, but it looks like it might be more complicated than it seems.

Yumi and Sachiko finally go on their date to the amusement park. However, Kashiwagi and Yuuki turn up, with Kashiwagi bearing a certain agenda in mind. Yumi learns a few things and Kashiwagi's intentions are made clear.

Tōko suddenly shows up on Yumi's doorstep in a strange situation and ends up being over for dinner, while Suguru and Yumi have an agreement. As well, Rei and Sachiko have an understanding.

The Yamayurikai Christmas party takes place. Tōko and Kanako are both invited to the party, but afterwards, Tōko rejects Yumi's offer of the rosary, and Yumi is crushed.

Yumi and the rest of the Yamayurikai are invited for a female-only new year party, where Yumi has an interesting dream that could be applied to her current situation.

With the elections for the next year's Student Council approaching, Tōko unexpectedly enters the race with murky intentions.

Sachiko and Suguru Kashiwagi discuss Tōko's entry in the Student Council elections and her recent behavior towards Yumi. The Lillian Newspaper Club organizes another card hunt event for Valentine's Day, while Noriko worries that Yumi has given up on Tōko. As well, the Gigantea soeurs have a small discussion about the 'next Rose'.

As different people in her life try to help her find happiness, Tōko continues to run away from their support. Suguru warns Tōko that if she continues to run away, one day no one will chase after her. More details of Tōko's family situation and her reason for refusing to be Yumi's petite soeur are revealed.

After Tōko realizes her large misunderstanding, crying, she is comforted by Noriko. The next week, the Valentines' Day Card Hunt for the Next Roses take place with surprising results. Sachiko and Tōko have an interesting conversation on the stairs, and eventually Tōko comes to realize something vital to her relationship with Yumi.

The Valentines' Day dates take place, with Chisato Tanuma finding Yoshino's card and Tōko finding Yumi's. During Tōko and Yumi's date, even more about Tōko's past is revealed, as well as her reasons for running away from home. They eventually visit the hospital owned by Tōko's grandfather, and Touko slowly starts to open up to Yumi. The season ends with Yumi's thought of Tōko accepting her rosary.