6:30 AM, April 21, 1648.
Inside the Inquisition Ship of the Testament Union deployed in Mikawa, Horizon Ariadust is joined by one of the ship's attendants in the room where she is held captive. The attendant asks her if she would want anything, and Horizon requests for a book to read, and to have her clothes back, since she was changed into a set of white robes since her arrest.
Meanwhile, in the ship's infirmary, Gin Tachibana looks over her husband Muneshige, who was still recovering after his defeat in the hands of Tadakatsu Honda. Gin takes the time to fill in Muneshige on the details, including Horizon's current identity as the automaton P-01s and her status as one of the Mortal Sin Armaments.
Gin soon feels that Muneshige is missing something. After his leg is healed by the spell that Gin placed on him, she forcefully reminds him of what he had to say to her, and Muneshige eventually apologizes for his rashness before thanking Gin and telling her that he has returned home.
"Tes. Welcome back." Gin's emotionless face manages to smile in response.
An hour later, the Musashi begins to move once again. The day after the destruction of most of Mikawa, evacuation procedures are initiated by the ship's captain, while President Sakai of Musashi Ariadust Academy considers himself as detained. Fortunately, one of the captains of the lesser ships of the Musashi, "Okutama", manages to negotiate into posting bail for Sakai.
Before he could leave, however, Sakai is interrupted by Galileo who accompanies Pope-President Innocentius. A scuffle that spans 20 years into the past is exposed, but Innocentius promises that he would be victorious when he forces Musashi to go into war with P.A. ODA. Sakai, of course, does not want such a scenario go unhindered.
In Musashi Ariadust Academy, the class of 3-Plum sorts out the details of the current situation.
According to Heidi, Horizon Ariadust currently inherits the power to rule over Mikawa, and she can represent Musashi and the Far East using that power; however, all that would be revoked if Horizon would commit suicide as of the Testament Union's sentence for her. Meanwhile, everyone is stripped of their political powers, and King Yoshinao of Musashi refuses to give out any statements.
What's much more troubling is that the class, lacking some of its students as absentees, does not share a single stand regarding the situation. Azuma is current grounded from leaving the dormitories due to "protection" by Far East guards, Naomasa is currently having a meeting with the Engineering Club of Musashi, while Nate is busy in a Nobility Club meeting with the local landowners. As for Masazumi, who manages to retain her position as Student Council Vice President, "he" is stuck with a predicament as well.
Heidi soon asks if there's anyone who would like to rescue Horizon, there are no hands raised. The reason, as Shirojiro explained, is because everyone wanted to know more about the situation.
With Heidi baiting him with a business chance, Shirojiro explains the effects of their decisions. If Musashi would defy the Testament Union, it would render the territory unable to replenish supplies and would cause famine for the 94,276 people in the Musashi, which only provides 10% of the population's food supply according to Ginji. Moreover, the current supplies of the Musashi can only last for two weeks.
Shirojiro, in spite of that grim scenario, points out that there's a way to resupply even with the show of defiance to the Testament Union, and that involves forcing Masazumi to join their side. But, they need to do something with Toori to make it possible.
Makiko soon arrives to start the class, and their activity for the class is writing essays with the topic, "What I Want To Do". After the explanation, she lets the class watch a live feed that shows the courtesy call between the forces of K.P.A. Italia and Futayo Honda's forces. What seems like a simple handover by K.P.A. Italia is more pressuring for Futayo, since she belongs to the Far East's severely limited forces.
In a show of saving face, Futayo proves that the Far East still has the resolve by attempting to steal her father's spear from Gin Tachibana's hands. However, Muneshige quickly blocks her attack, but it was followed by a calm handing over of the Tonbokiri, which was given by Tadakatsu Honda to the Tachibanas for safekeeping.
The 90-minute essay-writing session soon begins, and Tomo wonders what she wanted to write, and after imagining what would have happened if Toori was able to propose to Horizon at that time, her imagination overwhelms her. Her essay soon becomes too lewd even for someone like her, and she opted not to read it in front of the class. Because of that, Suzu is chosen to have her essay recited for the class, with Tomo reading the essay in her behalf.
Suzu's essay is a recollection of her past experiences with Horizon Ariadust and Toori Aoi, which started when they were small. According to her essay, she went to Musashi Ariadust Academy alone for the welcome ceremony, and she finds herself in front of an intimidating flight of stairs. When she started to feel down for longing her parent's praises, a young Toori and Horizon were there to help her up the stairs. Before long, she was able to trudge stairs by herself.
That day, she told her experiences to her parents, and it made them happy.
Years passed, and she was able to travel up those stairs by herself, but Toori would hold her hand once. At that time, Horizon is no longer there to hold her left hand.
In the end, Suzu wanted Toori to reunite with Horizon, whom she loves both, and as Tomo ends the essay, Suzu is on her chair, her concealed eyes filled with tears.
Then, all of a sudden, Toori appears in front of her, no longer the lethargic guy he appears to be a while ago, and as Suzu tries to show that she has matured (by letting Toori touch her breasts), he reveals that he has been "charging his gauge" the whole time, and this awards him a wall-breaking kick from a pissed Makiko.
The discussion in the class soon changes to their plans for saving Horizon, and with Toori wrapped like a dumpling and having no ideas on the next step, Shirojiro decides to step in. He plans on holding a Special Student Council Meeting, but Heidi points out that it is only applicable only if the Student Council President is in power; fortunately, Masazumi is still the vice president. Shiro then decides to use the only allowed condition for a Special Council Meeting, it is to pass a vote of no confidence for Masazumi.
Ergo, if Masazumi does not attend, the class can void Masazumi of her position by passing a vote of no confidence; otherwise, the class can hold a normal meeting.
In the Inquisition ship, Horizon manages to change back into her usual clothes in Blue Thunder, and she tells her attendant that she prefers the life in the snack shop than as a sovereign.