Games like Grisaia Phantom Trigger Vol.1
Games like Grisaia Phantom Trigger Vol.1 include Marco & The Galaxy Dragon, ATRI -My Dear Moments-, Tricolour Lovestory, Maitetsu:Last Run!!, and NEKOPARA Vol. 1. We matched them by the tags players give Grisaia Phantom Trigger Vol.1 on Steam (Visual Novel, Casual, Adventure, Anime, and Violent): closest matches first, and among equally close ones the better-known games.

Marco & The Galaxy Dragon
Shared: Visual Novel · Anime · Adventure

ATRI -My Dear Moments-
Shared: Visual Novel · Anime · Cute

Tricolour Lovestory
Shared: Visual Novel · Anime · Casual

Maitetsu:Last Run!!
Shared: Visual Novel · Anime · Casual

NEKOPARA Vol. 1
Shared: Anime · Visual Novel · Cute

NEKOPARA Vol. 0
Shared: Visual Novel · Anime · Cute

Tiny Bunny
Shared: Visual Novel · Story Rich · Horror

Doki Doki Literature Club Plus!
Shared: Visual Novel · Anime · Cute

Senren * Banka
Shared: Visual Novel · Anime · Casual

NEKOPARA Vol. 2
Shared: Anime · Visual Novel · Cute

NEKOPARA Vol. 4
Shared: Visual Novel · Anime · Cute

Mirror 2: Project X
Shared: Visual Novel · Anime · Casual

NEKOPARA Vol. 3
Shared: Anime · Visual Novel · Cute

Danganronpa Another Episode: Ultra Despair Girls
Shared: Anime · Visual Novel · Story Rich

Stella of The End
Shared: Visual Novel · Adventure · Anime

Florence
Shared: Casual · Adventure · Cute

MiSide
Shared: Cute · Story Rich · Anime

Danganronpa V3: Killing Harmony
Shared: Visual Novel · Anime · Story Rich

Magical Girl Witch Trials
Shared: Visual Novel · Cute · Story Rich

eden*
Shared: Visual Novel · Anime · Adventure

Summer Pockets
Shared: Visual Novel · Casual · Adventure

The Hungry Lamb: Traveling in the Late Ming Dynasty
Shared: Visual Novel · Adventure · Story Rich

Danganronpa 2: Goodbye Despair
Shared: Visual Novel · Anime · Story Rich

Fox Hime Zero
Shared: Visual Novel · Anime · Casual