Preioulsy Kurumi Tohisaki from a future in the next few days, requested aid from Yoshino and Yoshinon to get help from Momonga through Cocytus. Momonga with Albedo and Demiurge in the Round Table Room come to finally meet Cocytus who called Momonga for a meeting with Yoshino and her puppet. Momonga listens to Yoshino's story that she traveled from the future, which normally he would find unbelievable, but give Kurumi' abilities cannot disregard it not being true. Plus the description of E-Rantel and Nazarick's plans that an outside should not known given her brief time in Nazarick all convince him that Yoshino is telling the truth. He agrees that they must work together to carry out Future Kurumi Tohisaki's plan. Both Yoshino and Yoshinon thank the undead as they cannot save the others without him.
Momonga learning of the destruction of E-Rantel in the alternate timeline wishes to avoid the scenario. SO far it seems that their enemy uses Kurumi Tohisaki's own shadow to travel and attack. Still this means that with Kurumi Tohisaki in Nazarick an invasion is also possible. Cocytus offers to send his forces to deal with the threat, but Momonga reigns his warrior down as he trusts Cocytus's preparation a full blown battle in the dungeon is not a path he wants to take. Fortunately, is there a high probability that an enemy will appear in E-Rantel on a specific day. And now thanks to Kurumi's power of Zafkiel, she brought them valuable information on how to change the disastrous future.
Demiurge also listening to the conversation advise they place Solution Epsilon and a Shadow Demon to monitor Kurumi. Albedo also agrees that they can place Shalltear Bloodfallen on standby at the 9th Floor. Yoshinon notes that they are prepared, which Momonga explains that they are moving appropriately to deal with the "Eyepatch Kurumi Tokisaki". Suppose that Shido Itsuka and Kurumi Tohisaki and the latter's double attacks, Cocytus will be present to wait until she appears along with the rest of Nazarick's forces. He warns them that what they could be doing is dangerous as their enemy also could be aware of any changes in the time axis. They should be able to prevent the fatal future so long as Shido and his friends remains outside of Nazarick. Demiurge states that they should still try to neutralize or capture the Eyepatch Kurumi on the spot. But if not they should avoid giving any information to Kurumi Tohisaki as she might be unintentionally giving the enemy an ear into their plans.
Yoshinon notes that Shido will need to know. Albedo tells the puppet that they will leave it to her to disseminate the news to her friends and prepare them for their plan to trap the Eyepatch Kurumi. However she asks if there is anyone on their team suitable for keeping this kind of secret? To the puppet's knowledge the only ones she knows that fit the criteria are Kotori Itsuka and Origami Tobiichi. As for the others Demiurge feels that the less people know the better. For a while Momonga and the others came up with a strategy with Yoshino and Yoshinon.
Episode 2: Look
Yoshinon and Yoshino later are seen speaking with Cocytus on preparing for the upcoming battle. Cocytus admits that there is a small chance they could fail, but his new friends states that its okay. To prepare Yoshinon asks if Cocytus is willing to train them as it will be necessary for them to fight. This way it will be also very fruitful to get to know each other's strength. Cocytus finds that acceptable and the group agree to meet tomorrow on the 5th Floor. To avoid any suspicions Cocytus advises them to inform Shido and the others so they do not get worried.
Episode 3: Discipline
On the next day onwards, Yoshinon, Yoshino and Cocytus were training in the 5th Floor doing a mock battle. Yoshinon goes in her Siryon form and shows Cocytus her power. He comments that her defense power is high as well as her attack power. Yoshino thanks the insect for his compliment. Cocytus thought is a bit envious as he himself lost his power when fighting against an unknown enemy. The two talk about habits in battle and how sometimes unconscious methods are a giveaway. The two then resume to train on the defensive tactics. They are later joined by Narberal Gamma and Lupusregina Beta who were called to assist by Cocytus. To help Cocytus all four female agree to fight against Cocytus to help him improve.
Episode 4: Suddenly
A day before the day when the Eyepatch Kurumi is expected to appear in E-Rantel, Yoshino and her friends have been with Lupusregina and Narberal. The mock battle was repeated and later Yoshino expresses that she is having a terrible experience especially during the duels she had where he was still getting used to fighting. Yoshinon tells her she did okay and that she was lucky as the maids were going easy on her. Now she is just glad that they can return to their room to rest. Suddenly Shido appears and is surprised to see her. The two swap stories of their time in Nazarick, with Shido telling her he and the other girls have been providing Nazarick with information on the Angels they possess. Though lately he noticed Yoshino and her puppet to be absent. Yoshino tells she is fine and has been training with Cocytus and the others.
The two have an awkward conversation, when Shido finally asks Yoshino if she would like to date him to her surprise. Later on the 6th Floor, Yuri Alpha tells the couple that she will pick them up, and that Aura is keeping watch somewhere. After the maid leaves the two admire the stars on the ceiling, commenting that its nothing like the sky back in their city. Shido confesses that he wanted Yoshino to see this sight. Yoshino touched, thanks him though Shido jokes that she should be thanking Momonga who also help make Nazarick. Yoshinon asks why Shido is unprecedentedly romantic and asks him what he wants to do on a date like this. Shido whispers of course to play hide-and-seek.
Episode 5: Hide-And-Seek
In the forest on the 6th Floor Yoshino finds Shido. Shido claims that he intentionally allowed her to find his footprints that he placed to draw her away but is disappointed she still found him. Yoshinon explains that even with such camouflage work her eyes can't be deceived. That being said the local magical beasts knew where Shido was which Yoshinon wonders if it can be counted. Shido assures her its his loss. The boy informs her that they better wrap it up soon as Yuri will pick them up soon. Not only that Tohka and the others will be waiting. Yoshino agrees but finds she was glad to play hide-and-seek with Shido nonetheless. The feeling is mutual with Shido though Yoshino's alter ego Yoshino senses something is amiss and asks why Shido really wanted Yoshino to go out with him on a date.
Shido tries to say he was always interested in Yoshino's charm but then stops before apologizing. Shido tells Yoshino and Yoshinon they are right that something is strange, and explains that it was not his idea. Later Yoshino and Yoshinon are seen confronting Cocytus who admits that he asked Shido to go on a date with the two. Remembering that Yoshino was looking down, he mentioned it to Shido who offered to go out with the girl to cheer her up. Despite the deception, Yoshino sees that it was well intentioned and talks the Floor Guardian. The Floor Guardian apologizes for ruinin the date for her, as he wanted her to enjoy herself before they go into battle. Yoshinon catches that Cocytus is shy at his own feelings much to the insect's embarrassment. Yoshinon playfully asks if Cocytus would like to go on a date with her once the battle is done. The insect surprised accepts. With the two honing their cooperation and having built a friendly relationship, Yoshino was fully prepared for the decisive battle. Though Yoshinon questions if this date has anything to do with his obession regarding Momonga's succession.
- This character scenario was released alongside Date A Nazarick II.