This is the toughest challenge of your life. The final sections really deals with death and destruction.
New York Combat Revue Move Out!
Before this you have to get their motivations up. Choose either "We never give up" or "We'll make our own miracle" followed later by the analog lips which automatially put all your girls in its highest motivation (the girl you chose for the ending will have highest motivation and coupling enabled for the remainder of this game). But if you choose "We find our own way" or let the timer run followed by lowering the analog down on the analog lips, the consequence is your allies are going to end more easily.
Note: There's a total of six battles, apart from Ratchet, make sure you use protect and help me on all girls as it will help you fight against Nobunaga's Demon Form at the final battle.
Special note: The girl with the highest trust, will have her dialogue at the analog lips by letting the timer run out. Call it a special moment.
Aran in Danger!
You're job is to protect the engines and the manhole. Don't bother using supermoves on the sides in the air unless you're in danger. Get Subaru due to her wide range attack to do normal, joint and supermoves attacks to help protect the manhole. Do your best to take down the air bombs and keep your crew defence up so they last long enough before one or more crew has ended their duty. Stick to joint attacks in the air and remember to bring one or more of your crew into repair. Most of all, minimize as many flying robot minions or else one or more girls could be wiped out, costing the strength to the overall team.
Be really mindful for every one crew is lost, their abilities may plummet gradually so do your best to protect them all the way to the grand finale.
Special tip: If you're up to this point on your second or more walkthrough, you should have ten medals by now in order to get the Supernova attack. The Supernova attack is having you and all girls use a devastating powerful attack which wipes everyone off the area! It will save you huge amounts of time and will no longer worry about your crew dying.
Be forewarned that your only allowed to use the Supernova in this episode. Even if you transfer battle data to your new game, you might have to start all over again. If you chose Ratchet as your girl, your supernova might be replaced later in the episode. Last of all, you only get the ten medals here. You'll go back to nine medals when you start a new game.
If you're curious, Mr Sunnyside and his remaining team storms the Statue of Liberty to use the rockets to delay the 6th Heaven from reaching the Earth. There's a surprise for you!
Coupling tip: Apart from Ratchet, this is the point in building up motivation. Call the girl who you love the most because if she falls out of battle, you're going to have to protect her on the next battle or do the coupling could easily become useless. Speaking of which, each battle, protect and call one girl at a time, to build each of their motivations until the end and the mobility gauge might slowly update for you. Remember it well and it will payoff making it easy for your team to survive.
Travelling to Nobunaga's Chamber
It's pretty much a simple task with deadly danger. You have to bring your crew to the coffin at the other end and destroy it. Make sure to destroy the generators so the robot minions won't hurt your chances even further. Keep your defence up as much as you can because of the cannons as they may target and fire at your crew.
Use the defence strategem for this task. Divide into two groups. Three on the left and three on the right. Use joint attacks to take down a few enemies and barriers to get to the other end where the robot generators were. Send one person like Shinjiro to attack the coffin blocking your path to the entrance. Depending on who you choose for the finale, Nobunaga will make the person "the love" disappear.
Ratchet's Final Attack
If your playing Ratchet's ending, you get an extra scene for you to perform. You have to defeat the remaining robot minions with Ratchet's STAR once more. You can control her but cannot use Supermoves and Joint Attacks. Perhaps the only time of doing so. Also, your supermove is permanently replace with Ratchet's coupling so you might have a great advantage for the remainder of the finale.
Star Division face its darkest fears
You lost hope after Nobunaga makes all the girls disappear, making you lose faith and allow the dark pneuma to consume you. The girls your using for this moment will face the fears they need to overcome. So follow this task: taking down your ultimate mirror foe. In other words, use your supermoves and all attacks for at least two to three turns. Next its using joint attacks, supermoves and regular moves on Dark Shinjiro.
If done right, you'll be able to use Shinjiro in the final battle. Do your joint attacks and to take down enemies from left and right with the hands before taking down Dark Shinjiro as he foreshadows how tough Nobunaga is.
For the girls own special dialogue, choose "Surrender now". Each girl has their own say in supporting you.
Final flying battle with the golden mask
This would be tough if you can't keep your crew alive against Tenkafubu. Always keep healing and defence up for this one. Take down the first four horns at the top to get a head starts. Also take down the tail and the two horns at the bottom. Then take down the four arms in the middle before taking on the head to end the boss fight for this one.
Due to how much damage your crew take, it's best to keep your group in a tight pack that allows you and Diana to keep healing your group. With defence seriously needed, it will take a while until things finally blow over.
Nobunaga 6th Heaven Last Stand
Nobunaga hasn't admit defeat yet. So this is the last battle using your STAR. He'll change to Overlord Nobunaga to crush you with his devastating superpowers and if you see the circles, move out of the way! Make sure you get the right distance to do team attacks and by chance, use your supermoves. It will take very long to beat but eventually you'll succeed. Be sure to give all you got as this is the ending you've been waiting for.
The Last Goodbye
Eventually, you allow Nobunaga to be apart of you after his monster version has been defeated. Because of that you have free time to say goodbye to everyone before returning to your apartment. This marks the end credits. The good news is you get an extra chapter to review what you unlocked so far and for your second play through, you'll also be glad to save your battle experiences so the next time you play, you'll have less trouble taking down enemies that has given you a hard time the first time you play but it only applies to you. Your crew will not be affected so remember to suck up to them if you want any easy battle to play through. However, their relationship between each other will remain strong so you will have easier time when it comes to teamwork.
Thank you message: If you finish the game at least six times with ALL girls in each playthrough, you'll get the nicest message you'll get after the credits finished.