STEINS;GATE RE:BOOT Email Answers & Phone Trigger Choices
Look up STEINS;GATE RE:BOOT email answers by chapter, sender, subject, and reply. Flags, achievements, collectibles, and optional mail are tagged.
Use this as a lookup table. Ctrl+F the subject. Type tells you whether the reply is a true-ending flag, an achievement, a collectible, or optional flavor.
Achievement Kurisu mail and true-ending Kurisu mail in Chapter 4 are different. Save if you want both.
| Chapter | Sender | Subject | Reply | Result | Type |
|---|---|---|---|---|---|
| 1 | Mayuri | Upa… | Upa. then Kakeru-kun | Resonant Reaction; RaiNet batch 1; RaiNet’s Mascot | Achievement + Collectible |
| 1 | Faris | The decisive battle is close at hand nya | Red Southern Cross | Princesses of Chaos progress | Collectible |
| 2 | Lukako | I made sweets. | Family → My sister | Cruel Sister (needs Mayuri call 8/01 14:29) | Achievement |
| 3 | Lukako | About Frogs | Gero Froggies | Frog wallpaper batch 1 | Collectible |
| 3 | Faris | PHANTASM is the cat’s meow | Theme Song → RaiNet Kakeru | RaiNet Ep. 13 attachments | Collectible |
| 4 | Suzuha | Akihabara’s | peaceful | Warrior Girl’s Pride | Achievement |
| 4 | Kurisu | Did you write it? | Report → Cup noodles | Discontinuous Qualia | Achievement |
| 4 | Kurisu | Did you write it? | Scientist → … → Why am I still here? | Flag 1; Genius Girl’s Melancholy | True Ending Flag |
| 4 | Faris | Sign of increasing misfortune | He → NyanNyanian | Cat’s Tea Time | Achievement |
| 4 | Faris | Sign of increasing misfortune | He → Chinchilla Start → Ep 8 | RaiNet final batch; Hero of RaiNet | Collectible |
| 4 | Mayuri | Speaking of lotteries | Magazine → Crunchy-kun → Kakeru-kun | RaiNet mid batch | Collectible |
| 4 | Lukako | About RaiNet | (open attachment) | RaiNet summaries | Collectible |
| 5 | Mayuri | What made me happy today | cosplay | Passions Best Forgotten | Achievement |
| 5 | Mayuri | What made me happy today | Fubuki-chan and Kaede-chan | Princesses of Chaos | Achievement |
| 5 | Kurisu | Plans | Traveling expenses | Flag 2 after follow-up mails | True Ending Flag |
| 7 | Kurisu | The key (ﾉД )</td><td style="padding:8px 10px;border:1px solid #5c4328;vertical-align:top">I don't have a key → Security → Reality</td><td style="padding:8px 10px;border:1px solid #5c4328;vertical-align:top">Flag 3</td><td style="padding:8px 10px;border:1px solid #5c4328;vertical-align:top">True Ending Flag</td></tr><tr><td style="padding:8px 10px;border:1px solid #5c4328;vertical-align:top">7</td><td style="padding:8px 10px;border:1px solid #5c4328;vertical-align:top">Kurisu</td><td style="padding:8px 10px;border:1px solid #5c4328;vertical-align:top">The key (ﾉД ) | I don’t have a key → Frog | Frog batch 2 | Collectible |
| 7 | Kurisu | The key (ﾉД `) | Home → Hyahha → I’m gonna give it to you straight | Frog batch 3; Froggy Fad Demise | Collectible |
| 8 | Kurisu | Explain yourself! | (only reply) | Flag 4 after From an unpopular girl | True Ending Flag |
| 9 | Kurisu | Contact me, idiot! | Worried | Flag 5 | True Ending Flag |
| 10 | Kurisu | Where are you now? | Ignore / or Where you are | Kurisu ending vs Flag 6 | True Ending Flag |
You cannot cancel a selected reply in RE:BOOT. Save first. Inbound mail is easier to miss than in the original (KKB). Full chapter context: Walkthrough. Flag write-up: True Ending.
Last verified: August 21, 2026. Steam app 4012810. Uncertain items are marked not yet confirmed.
Sources
- Kiri Kiri Basara 100% Guide (Martin, 19 Aug 2026)
- Kiri Kiri Basara review (13 Aug 2026)
- Kiri Kiri Basara Digital Deluxe review (15 Aug 2026)
- Official English site
- Steam store
- Steam achievements
- Videos used as research (facts extracted, not copied): KKB 100% Guide, KKB review, Noisy Pixel review
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