Gal*Gun: Double Peace: True Ending (How To)

Here are some links that quite helpful in telling you how:
Gal*Gun: Double Peace Trophy Guide and Road Map
Quick True Ending Choices route guide
Easy to use Guide to platinum ​Gal*Gun Double peace

Now you maybe asking why bother writing some more if you're going put up some links. I will tell you why; the reason is that I don't have to repeat what already stated on those link and only mention what not mention on those links. Another reason is that I purposely have look for these guide to find the final True Ending for myself. I got all the true ending trophy but one so I have look it up and while I'm at it might as well write how to get it in a simple form.

Here some quick Facts (from my personal gameplay experiences) like a per-requirement for True Ending:

• 51% (or higher) Affection will get you Good Ending route but can change to True Ending based on what you do during the final chapter and get 100% in the end. (You get the True Ending if you have the other requirement listed below) 
• You need to get Rank A before any interaction or final event stage for the final chapter for any heroine route for a True Ending (One of the link above stated you need Rank S, which is not true because I personally confirm this with Rank B and Rank A on several route. Rank A will get you True Ending if the other requirement are met, Rank B will get you Good Ending even if the other requirement are met.)
• If the Heroine Route you chosen have a [Final Doki-Doki], make sure you get a [Double Peace] (max gauge) to get True Ending. (you will get Good Ending if you push the "finish" button on the [Final Doki-Doki] before the "max gauge" even if met all the above requirement)  

You can read the above links and follow what they stated or do your own thing and solve things on your owns (which what I mostly did). I will list based what game states as True Ending and its trophies. Don't forget the quick fact I mention that will apply on the True Ending.

This should already being mention in the game but the choices of dialogue your character can chose  is based on your character's parameter (this apply to all route expect the True Love Route). On the Unseen Destiny (True Love Route) your character's parameter will affect what type of female will come out and attack you.

[The dialogue uses for each routed is based on the above links walkthough and restated here (FYI, this route is heavy on Lewdness checks)]   
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I love Shinobu (Shinobu Route)

• Shinobu's True Ending
• Teach her body directly 
• Try to be more captivating
• *strokes*
• I'd swipe the panties if they were yours
• I love you
• You're beautiful like a Goddess
• Go right in!
• I'll not pass off Shinobu to you!
• I was worried about you
• Show me your smile
• I can't do that!
• Maya-chan isn't weak!

I love Maya (Maya Route)

• Maya's True Ending
• I was just looking at you
• I'm good at using the ol' noodle
• Your cute face is a mess...
• *hug her tightly*
• Show me where you're injured
• Talk about what goes with rice.
• *stroke her*
• I'll do whatver I can!
• *keep quiet*
• Here, let's rehydrate!
• Thanks for telling me
• Maya-chan is the stupid one!

I love both (Sisters Route)

• Sisters Route's True Ending
• You two look great in your uniforms
• The seal has been broken
• You don't have to do it if it's bad
• You got some nice air on that jump
• You must be good at sports
• How does this work?
• That swimsuit looks good on you.
• You must be really motivated now
• I'll back you guys up!
• Let them go!
• Did you see how brave I was?
• I want the three of us to be happy

I have no idea (Angel and Devil Route)

• Ekoro's True Ending
• You activated my trap card!
• Shout real loud! Scream "dumbass!"
• Gotta stop them, even by force
• You're not a doll
• Ekora is right, help Kurona first (Route Split)
• I'm a man! I can't help it!
• I wanna get more physical...
• *shout in the 2nd controller's mic!*
• Should I get you some medicine?
• Will she really return to normal?
• Kurona's True Ending
• You activated my trap card!
• Shout real loud! Scream "dumbass!"
• Gotta stop them, even by force
• You're not a doll
• [Place holder]
• We gotta go help!
• It's a battle of wits!
• Let's carry them to the infirmary!
• Well done, Kurona-chan!
• What's wrong with a make-up lesson? (100% by now if you follow this)
• [Place holder]
• [Place holder]
• Patako's True Ending
• Required you to already gone through all the other True Ending
• Follow Kurona (devil) route until the last part (read link for more info)
• Help me, Ekoro! (Route Split)
• I need to find a girlfriend...today 

Unseen Destiny (True Love Route)

• True Love Route's True Ending (any other female) 
•  No dialogue required, just your scores and level of affection

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Any Time on any Route

• Aoi's Ending 
• The girl at the Academy Shop, just "Donate LOVEHEARTS" until the last payment (9999). At this point you be ask if you want to join her band to America as their band manager. Chose the one where you go with her to America.