Spring, a Date, and Playing a Little Sister

Spring, a Date, and Playing a Little Sister (春とデートと妹ごっこ) is a Drama CD released on January 6, 2012. The story takes place between the events of Pentagon++ and Nise Random. This Drama CD marks the debut of Uwa Chihiro and Enjouji Shino's voice actors.

Summary
One day, the five original members of the Student Cultural Society find a mysterious note. On the note, they find the scribbled names of the five second years and a message: "You must grant the wishes of Uwa Chihiro and Enjouji Shino, otherwise bad things will happen." Believing it to be the work of No.2, the friends decide to obey the bizarre note. Asking their underclassmen what they can do for them, the Pentagon endeavor to do their best to grant any wishes Shino and Chihiro may have.

Synopsis
On an otherwise normal day, the five original members, or "Pentagon", of the Student Cultural Society come across a bizarre note. On the note are the names of the five second years, a few stars, and a message saying "You must grant the wishes of Uwa Chihiro and Enjouji Shino otherwise bad things will happen." The Pentagon suspect that No.2 is behind the note since a similar message preceded the Time Regression phenomenon.

Shino and Chihiro soon enter the clubroom, surprising and startling the second years. Inaba calls all the second years to the hallway for a private meeting. At that time, they remember Shino having mentioned something about wanting to eat parfait. Just as Aoki denies that could be a wish, he suffers a stomachache and rushes to the restroom. The remaining members realize that getting sick could be a consequence for disobeying and, considering No.2's past actions, the friends decide to grant the wishes of Chihiro and Shino.

The seconds years offer to treat Shino and Chihiro to parfaits and Aoki suddenly returns, his stomachache gone. Knowing that this cannot be a coincidence, the Pentagon invite Chihiro and Shino for parfaits at a family restaurant while keeping the content of their conversation a secret. At the family restaurant, the StuCS enjoyed parfaits together and fooled around a bit with Aoki asking Yui to feed him. Yui ends up tricking Aoki and ate the entire parfait quickly. Shino then mentions how feeding each other seems like a thing couples would do and, after some unnecessary comments from Nagase, Shino becomes curious of what Taichi and Inaba's dates are like. Knowing they must grant any wish, Taichi and Inaba decide to go on a date and let Shino and Chihiro follow to observe.

During the Golden Week holiday, the StuCS meet up. Taichi and Inaba are uneasy and embarrassed about letting others watch their date, but seeing no other choice, they decide to do it for the sake of the StuCS's peace. Taichi and Inaba quickly have a brief argument on where to go first, either the Electronics shopping area or Pro-wrestling match first. They end up going to the Electronics shopping area first, Taichi stating, "Inaba is important to me, so I'll go wherever Inaba wants to first." Inaba reacts cutely and Nagase labels this side of Inaba, "Dereban". While they are in the shopping district, suggestions by Nagase, Yui, and Aoki make Shino want to see Taichi and Inaba hold hands. The two proceed to hold hands but are embarrassed about it.

Later, the gang passes a cosplay shop which is holding a contest to dress up as a character and the winner will receive ￥15000. Shino insists that Nagase should enter the contest and Inaba teases Nagase, reminding her that she can't refuse. Nagase obeys and dresses up as a Mahou-shoujo (magical girl). The friends later go to a parfait shop where Shino wants to see Inaba feed Taichi a parfait. Embarrassed and a bit angry at the others who keep giving Shino suggestions, Inaba went on with feeding Taichi. Unfortunately, she was very violent with her feeding and missed Taichi's mouth and hit him in the face, knocking him over. Inaba started crying and thought Taichi was going to die, but luckily it was just an overreaction on Inaba's part.

At sunset, the group went to watch Pro-wrestling. The opening act involved an audience member to fight a "stupid wrestler" for entertainment. Shino and Chihiro wanted to see Yui being cool so Yui having no choice entered ring and performed some karate moves. Shino admired Yui's strength as a girl and the seconds secretly talked about Yui finally overcoming her Androphobia. After finishing the show, they coincidentally encountered Fujishima on her jog. Fujishima still a bit depressed about losing the election for Class president noticed that Taichi is always surrounded with girls and getting along with them well. She then remembered Watase's observation that Taichi might have a harem which made Shino and Chihiro interested to see what if Taichi went on a date with Yui and Nagase. Aoki and Inaba were shocked but knowing that this is a phenomenon they had no choice. On the next day, they met up again. Yui was wearing something different from usual which Taichi noticed. They only walked around and talked but Inaba and Aoki were following from behind enraged. They encountered Gotou and Fujishima again and they confirmed that Taichi does actually have a harem. After Gotou left in shock and anger not before telling Taichi that he'll take off 30 points off his test, the group continued their way home. On their way Nagase asked Shino that she likes Taichi's voice which suggested to Shino making her next wish. She wishes for someone with Taichi's voice to confess to her. Because of the phenomenon, Taichi had no choice but to think of a way to confess to Shino while Inaba was angry once again. On the next day, Taichi called Shino to a shrine near the school and said there was something important to talk about. Shino nervous waited for Taichi to speak. Taichi confessed to Shino saying "I love you, be my little sister." Shino shocked and extremely happy was speechless and then started stumbling on her own words. Later that day, Shino called Aoki for advice but only to be told to go for it from Aoki. The next day, Taichi and Shino met for a date. Taichi told Shino that she doesn't need to use polite language and call him "onii-chan". Shino embarrassed but still called Taichi "onii-chan". Taichi extremely happy as well collapsed and was also speechless and said, "my own little sister is number one in the world, you can be number 2" After too much embarrassment, they decided to call each other normally. The two went on a date but Shino noticed a group of suspicious people wearing sunglasses and masks were following them. One of the suspicious people went right up to Shino enraged but not before the others apologized and dragged that person away. Shino noticed that their voice was really familiar. The suspicious people gathered without Taichi and Shino knowing and turned out to be the rest of the members of the StuCS. Inaba could not stand Taichi being with Shino over-reacted but was stopped by the rest. When the date was over, the two went different ways home. Taichi instead of going home went to a group of people which Shino recognized as the suspicious people tailing them on the date. She realized that they were the second years in the StuCS. Not sure what the date was about whether it was a joke or serious she went home. At school, Enjouji and Chihiro were alone in the clubroom after school. They heard some noise outside of things falling. Shino wanted to go check it out ut was stopped by Chihiro. Chihiro suspected that something was up with the second years and suspected that they were granting their every request. To test it, he made a request that made Inaba angry and rushed in and the room started to become chaotic. Shino having enough of it yelled angrily to tell everyone to stop and asked the second years why they were doing what they did. Taichi and the others knowing that they can't mention Heartseed only told them that they wanted to make them happy. Shino remebered about the piece of paper she wrote and asked them if they mistook that paper for a command, Shino then explained that it was just a piece of paper with a spell written on it that she learned about from a book. With everything cleared up, they resumed their normal activities. Later that day, when Chihiro was returning home, he realizes that the second year's actions were driven by Heartseed. Because two weeks ago, Chihiro was approached by Heartseed being asked if he wanted power. Heartseed told him that he only had to do one thing successfully and that power would be his to keep.

Cast

 * Mizushima, Takahiro as Yaegashi Taichi
 * Toyosaki, Aki as Nagase Iori
 * Sawashiro, Miyuki as Inaba Himeko
 * Kanemoto, Hisako as  Kiriyama Yui
 * Terashima, Takuma as Aoki Yoshifumi
 * Tōyama, Nao as Enjouji Shino
 * Toyonaga, Toshiyuki as Uwa Chihiro

Trivia

 * This drama CD explains the situation in how Chihiro got the power of "Illusionary Projection" from Heartseed.