In the Den of Darkness, Rasetsu is angered over Setsuna's defeat and plans to get revenge on the Imperial Assault Force.
Meanwhile, Kanna and Sumire are rehearsing their lines for the next performance, though it was only a matter of time before an argument broke out. Iris was starting to bug the others, and just decided to leave.
Ichiro managed to finish sorting the vouchers for the day when Sakura asked if he had seen Iris. She asked if he could help clean up the large prop storage room (You can choose to accept or decline the invite.) Ichiro then finds Iris later on and asks him out on a date tomorrow.
This was a very surprising question, but the reason she asked is that tomorrow is Iris' birthday. Sakura suggests taking up her offer, since birthdays come around only once a year. After that, he helps Iris choose the outfit she'll wear tomorrow. The next day, he decides to get ready for Iris' date. (Depending if you help Sakura clean up the storage room or not, Ichiro will still continue on his date with Iris). After speaking with the others, he heads to Iris' room and the two head out for their date.
At the railway, Ichiro suggests heading to Asakusa. Iris heard a lot about it from Kohran so she really wants to go there. After going through the park, she says that she will be 10 years old today. After walking for awhile, they head for the shops where Ichiro buys her a present. They then head for the motion picture theater, where Iris' powers suddenly grows out of control and causes an earthquake.
After helping Sakura clean out the prop room, everyone finds Ichiro in his room and gives him a note from Iris that she ran away. As they begin grilling him for information, Kohran comes up with a solution: a new "Mr. Truth" lie-detection device. After a series of questions, turns out Ichiro really didn't know where Iris went. Everyone searched the whole theater, but found nothing. Ichiro finds a picture diary in Iris' room that says she went for Asakusa. After looking all over for her, he found her at the park. Iris is angry at Ichiro for not going on a date with her, and her power surfaced, leveling the park fountain in the process.
Yoneda give Ichiro a real tongue lashing about the past day's events. Even after the scolding, Iris runs off. Ichiro finds that Kohran, Sumire, and Kanna were eavesdropping and saw her run off towards her room. After trying to talk to her, she wouldn't listen. After Kohran, Sumire, or Kanna tries to open her up, they figure that it would be best to just leave her alone for awhile.
While in his room, Ayame steps in and talks with him concerning Iris. She doesn't like being treated like a child and tries her best to act like an adult. The next morning, Ichiro tries to talk to Iris again, but it seems she's still mad at him and the others.
Later, Sakura comes to Ichiro with terrible news: Iris left the theater in a Kobu! Yoneda is a bit flustered that Iris left for the city in a Kobu. Ayame reports that she was headed toward Asakusa. But things go from bad to worse as Masou Kihei are also headed toward the same area. They now head out: to rescue Iris, and stop the Kuronosukai!
On arrival, they find Rasetsu getting a beating from Iris. After everyone finds her, she runs off again. Ichiro and Sakura chase after her while the others deal with the enemy. Ayame explains that being treated like a child has affected Iris greatly, so in order to calm her down Ichiro must remain true to himself. After managing to surround her, Ichiro managed to speak his heart out to her. This makes her open her hatch and jumps out to him, and gives him a hug.
Now that Iris has calmed down, everyone starts the battle anew.
"Imperial Assault Force, Go Forth!"
Maria indicates that Rasetsu is on the other side of the gate, but it won't be easy with the gate in the way. The mechanism for the gate should be able to open it, but none of their Kobu could leap over the walls. But with Iris' new Kobu, that problem was solvable.
Rasetsu vows to get revenge for Setsuna's demise, and asks who is most important to Ichiro. (Depending on the choice you make, either Ichiro or another member will be teleported inside the gate and surrounded by enemies.) After taking care of the surrounding mechs, Iris opens the gate and everyone charges in to face Rasetsu.
After a long battle, Iris uses her powers to fling the brute a long, long way.
When Sakura asks Iris what she felt when lept into Ichiro's arms, she felt really warm...and the rest's a secret!