This is a complete, spoiler-free 100% completion guide for STEINS;GATE RE:BOOT. It covers every ending, achievement, CG milestone, optional email chain, and the extra requirements needed for the Kurisu and True Endings.
If you are only interested in experiencing the story, you do not need to worry about most of the optional choices. The major ending branches begin between Chapters 6 and 9. At the end of each of these chapters, you will eventually have a choice involving a D-Mail or the PhoneWave. Choosing not to proceed will lead to one of the character endings, while making the required choice will allow the story to continue.
There are four character endings that can be reached this way: Suzuha’s Ending in Chapter 6, Faris’s Ending in Chapter 7, Lukako’s Ending in Chapter 8, and Moeka’s Ending in Chapter 9. If you continue through all of these chapters by making the required choices, you will eventually reach Mayuri’s Ending in Chapter 10.
The Kurisu and True Endings work differently. Throughout the game, Kurisu will send Okabe several emails that have specific responses. Correctly answering these emails gives you True Ending flags. There are six flags in total. You need the first five to reach Kurisu’s Ending, while obtaining all six allows you to reach the True Ending.
For a full 100% completion run, it is therefore important to make saves before the major ending decisions and before certain important emails. This allows you to experience an ending and then return to the same point without replaying large sections of the game.
Steins;Gate RE BOOT Walkthrough – Endings, Chapters Tips
The Prologue is completely straightforward, so you can simply read through it normally. There are no important decisions that need to be made for the ending routes during this section.
Once you finish the Prologue, you will automatically receive the “Prologue of the Beginning and the End” achievement.
After that, continue into Chapter 1.
Chapter 1
Chapter 1 is where you can start picking up several of the easier achievements. Most of these do not require any complicated choices, so it is worth taking a few minutes to experiment with Okabe’s phone when you first gain access to it.
Open the phone and look through your sent emails to unlock “Memories of the Self.” You can also look through your received emails to unlock “Memories of Another.”
While you are inside the phone settings, change Okabe’s wallpaper to unlock “Vision Projection.” You can also change the ringtone used for calls to receive “First Sound.”
Later in the chapter, you will reach the section where you need to enter a number into the PhoneWave. Before entering the correct number, deliberately enter an incorrect number ten times. The game will reward you with the “Homerun-level Clumsiness” achievement after the tenth incorrect entry.
Once you have obtained the achievement, enter 120# to continue the story normally.
Mayuri’s “Upa…” Email
At some point during Chapter 1, Mayuri will send you an email with the subject “Upa…” When you receive it, reply with “Upa.”
This gives you the “Resonant Reaction” achievement for replying to an email. Mayuri will eventually send another email in response. Open the attachment included with that email to unlock “RaiNet’s Mascot.”
This email chain is also important for the Hero of RaiNet achievement later, so make sure you complete it rather than ignoring the message.
Faris’s Email
Later, Faris will send an email titled “The decisive battle is close at hand nya.” Reply to her with “Red Southern Cross.”
When Faris responds, open the attachment in her email. This begins the requirements for the “Princesses of Chaos” achievement. You will not receive that achievement immediately because another Mayuri email chain in Chapter 5 is required.
Chapter 2
Chapter 2 contains an important email chain involving Lukako, as well as several optional phone calls.
Lukako’s “I made sweets” Email
Lukako will eventually send an email titled “I made sweets.” Reply to this email with “Family.”
Afterward, you will receive another email titled “About my family members.” Reply to that email with “My sister.”
There is an important requirement for this particular response. The “About my family members” email will only appear if you answer Mayuri’s phone call on 8/01 at 14:29.
After replying correctly, Lukako will eventually send an email titled “About my sister.” Simply reading this email will unlock the “Cruel Sister” achievement.
Identity of Complete Isolation
During Chapter 2, you will have opportunities to answer phone calls from Mayuri and Kurisu. If you ignore one of the required calls, you can unlock “Identity of Complete Isolation.”
You do not need to permanently ignore the call. If you want to preserve your normal story progression, simply make a save before the call, ignore it to unlock the achievement, and then reload the save afterward.
Answering Mayuri’s call will give you an additional scene involving Mayuri and Faris. Answering Kurisu’s call will cause Kurisu to join you at Yanabashi Shrine.
Neither choice is required for the major ending routes, so you can decide which optional scene you want to see.
Chapter 3
There are no major ending decisions in Chapter 3 if you are following the main progression.
At one point, Daru will call Okabe. Answering the call gives you an additional scene involving Daru and Mayuri, while ignoring it results in a scene involving Kurisu.
Completing Chapter 3 normally will unlock the “Butterfly Effect’s Divergence” achievement.
There are also two important collectible-related email chains associated with this chapter. If you are working toward Froggy Fad Demise or Hero of RaiNet, make sure you complete the relevant emails instead of skipping them.
Froggy Fad Demise — First Email
Lukako will send an email titled “About Frogs.” Reply with “Gero Froggies.”
Lukako will then respond with an email titled “More news about the frogs.” Open the attachment in this email and view all of the wallpapers.
This is the first batch required for “Froggy Fad Demise.” The remaining batches come later, so you will not unlock the achievement yet.
Chapter 4
Chapter 4 has several important email chains, including ones involving Suzuha, Kurisu, and Faris.
Suzuha’s Email
Suzuha will send an email titled “Akihabara’s.” Reply with “peaceful.”
Suzuha will eventually send another email in response. Reading that email will unlock “Warrior Girl’s Pride.”
Kurisu’s Email Chain
Kurisu will send an email titled “Did you write it?” Reply with “Report.”
Kurisu will respond with an email titled “Please?” Reply to this one with “Cup noodles.”
Later, you will receive an email titled “Favor to ask.” Simply reading this email will unlock “Discontinuous Qualia.” You can reply to the email if you want, but the reply is not necessary for the achievement.
Faris’s Email Chain
Faris will eventually send an email titled “Sign of increasing misfortune.” Reply with “He.”
She will then send an email titled “About abilities.” Reply with “NyanNyanian.”
Later, Faris will send an email titled “Cat tongue nya.” Reading this email will unlock “Cat’s Tea Time.”
During this chapter, you should also reach the 25% CG Achievement once you have collected enough CGs.
Chapter 5
At the beginning of Chapter 5, Faris will call Okabe. Answering the call gives you an additional scene with Faris, while ignoring it gives you an additional scene involving Mayuri.
The more important part of this chapter is Mayuri’s email chain.
When Mayuri sends an email titled “What made me happy today,” make a save before replying. First, reply with “cosplay.”
Mayuri will eventually respond with an email titled “The reason.” Reading this response unlocks “Passions Best Forgotten.”
After receiving the achievement, reload the save you created before replying to the original email.
This time, answer “What made me happy today” with “Fubuki-chan and Kaede-chan.”
Mayuri will respond with an email titled “Huh?” Read it to unlock “Princesses of Chaos.”
Using the save here saves you from having to replay the entire chapter just to see the alternate email response.
Chapter 6
Chapter 6 is where you need to start paying much closer attention to your saves because this is where the first major ending branch occurs.
At the beginning of the chapter, you can choose whether or not to call Mayuri. If you decide not to call her, you will see an additional scene.
Later, you will have another opportunity to call either Mayuri or Lukako. These calls provide additional scenes but do not determine the major ending.
At another point, you will have the option to call Kurisu, Mayuri, or Daru. Calling one of them gives you an extra scene with that character. If you choose not to call anyone, you will instead see a scene with Suzuha.
Suzuha’s Ending
Near the end of Chapter 6, you will reach the first major D-Mail decision.
Make a save before making the choice.
When given the option to send the D-Mail, choose to do nothing.
By refusing to send the D-Mail, you will be taken toward Suzuha’s Ending. Completing the ending unlocks “Irreversible Reboot.”
Once the ending is finished, reload the save you made before the decision.
This time, send the D-Mail.
Doing so will allow you to continue into Chapter 7.
Completing Chapter 6 will also unlock “Metaphysics Necrosis.”
If you have collected the necessary CGs throughout the earlier chapters, you should also receive the 50% CG Achievement around this point.