A Melancholy Intellect
There's really not much to Subaru's story except she, Diana, Cheiron and Rosita got into a combative war leaving them totally apart. So you try and get Subaru to open up to you which could prove to be a challenge.
Note: There's no free time so expect this episode to be quite short.
The trouble with Subaru
It's time to go around New York again. You should start off going to the backstage in which Subaru suddenly leaves Gemini. Then go to Battery Park in the earliest moment as your response will correspond to a girl except for Subaru. You'll meet Diana automatically at the construction site in which she's caught in Rosita's trap. A fun one is at Cafe Samba in which Cheiron tries to hypnotise Subaru but instead Rosita gets caught in the act!
Continue your exploration until the last possible moment if you have time left to go back to the theatre. If you reach the Hot Spring, Gemini gets soaked with water. If you're nice, choose "Wipe her body", but fool her by choosing "Take your clothes off" you'll get punch for being a pervert! She reveals that she's clumsy and leaves you in a hurry. You'll find out later on why she's depressed.
Note: It's up to you in your response as you go around New York. Which ever girl you like, you do have to balance out between the girls.
Shinjiro vs Subaru
If you reach this point after stopping Cheiron, Diana and Rosita trying to cause trouble for Subaru then follow those prompts wisely to finish this duel: You can choose to attack first or not, then parry her attacks either lower for the first time or permanently leave it in the middle the second time. Push for perfect on the minigame. Apparently Subaru is too good for you so lower it down with the control stick to give in. Understand that since this is Subaru's story, you don't want to aggravate it by not giving in to the duel.
Even though you lost the duel, there's another twist to this story.
Peppermint's Stage Debut
You're expected to perform on stage called "Viva Harlem" but the only problem is the audience expects to see only girls on stage! It can be a sexist world but that's the rule of children's anime TV shows. So when Cherry and Anri comes to your house, you have little choice but to dress up as a girl with a stage name called Peppermint. You might have fun going around as a girl but you also need to push all the girls motivations up. And how do you look? Pretty cute at best.
Remember, if your a boy, don't try this in real life! After all, you don't see this everyday! With Rosita at her house, if you're trying to convice her that you're a boy, whatever you do, don't choose "Take your clothes off"! Because Rosita is eleven years old, she's not old enough to even look at you to put it lightly. So she shoots your wig off and call you fake Shins! So much for flattery.
Of course to clear things up, your performance as Peppermint has a strong effect on Subaru. It's worth putting your best on the minigame as it will help with the battle which is coming up on the next section.
You'll be going on the ship dressed as a girl... again. To find Cherry and Anri, look to the very right and zoom as much as you can and focus to take a photo shot.
On the battlefield it's a time of desperation! You must move the statue to the entrance and if one of the statue escape by the robot minions, missions over. So go there and deal with it first and also take down the objects generating robots to make it easier.
The easiest way of doing provided how updated your fighter is, get Shinjiro to unblock the area on the left. Summon Subaru and push all three statues to the entrance. Then get Diana, to finish pushing the statues to complete the mission if Subaru doesn't have enough bars to push the statue through.
If you want Subaru to be highly motivated here's the answer: Choose "New York isn't rotten!" Followed by "Take down Tsugarubi". At the cutscene, choose "Make your peace monster!".
The battle for revolution
Before battle starts, you have to destroy the tank to save Diana, Cheiron and Rosita from dying in stone. Tsugarubi summons Enten for his final standoff. To complete Subaru's motivation choose "We're all friends". The order in which you need to defeat him might be easy if done right: Take out his tank in his back first. Get your girls on the other side to take out at least one of his arm that's a cross between an axe and a gun. With those parts gone, attacking the head where the pneuma is should be easy.
Here's the drill, if you already earned nine medals and Subaru reaches her motivation peak, use coupling where the tank and arms is. You know the rest from what's written above.
Coupling tips: If Subaru's motivation is still not high enough, help me and protect and stall until coupling is ready.
After the victory pose, Gemini is left and boy has she got a surprise for you!