Let me know in the comments if any links are broken and I'll do my best to find alternate links.
Update 1/9/2024 - Added Dancer Girls' Hangout Trails to Azure Drama CD
- Added No Boys Allowed! Makeover Time Trails to Azure Drama CD
Update 4/8/2024 - Added Mariabaell's (Love)Sick Visit Trails from Zero Drama CD
Update 8/4/2024 - Added Trails from Zero Drama CD - Drama Version: Stalker Investigation
Update 8/18/2024 - Added Trails from Zero Dram CD - Melancholy of the Bright Family
-TRAILS IN THE SKY-
Trails in the Sky Gaiden: The Tale of Loewe [MANGA] -- After Sky SC. Gives more insight into Loewe and the events of the first 2 Sky games.
Advance Chapter [DRAMA CD] -- After Sky the 3rd
Ring of Judgment [MANGA] -- Details events of Estelle and Joshua after Sky the 3rd but before Zero.
-FROM ZERO TO AZURE-
Four Destinies [LIGHT NOVEL] -- Details the main cast prior to Zero. Does contain some spoilers so you might want to hold off until you finish Zero.
Tio's Best Partner [DRAMA CD] -- During or after Zero. (Text Version)
Mariabell's (Love)Sick Visit [DRAMA CD] -- During or after Zero
Trails from Zero Drama CD - Drama Version: Stalker Investigation -- This is a Drama CD version of an in game event, best to do after finishing Zero.
The Melancholy of the Bright Family [DRAMA CD] -- After Zero
Road to the Future [DRAMA CD] -- Watch before starting Azure.
Catfish HotPot for Dinner [DRAMA CD] -- Best watched during or after Azure
If Cecile Got Angry [DRAMA CD] -- Best watched during or after Azure
The Dancer Girls Hangout [DRAMA CD] -- Best watched during or after Azure - select closed captions for English.
No Boys Allowed! Makeover Time [DRAMA CD] -- Best watched during or after Azure - select closed captions for English.
-TRAILS OF COLD STEEL-
Links of Heats Case A.R. [MANGA] -- During Cold Steel preferably after Rean and Alisa are cool.
Returning Home [DRAMA CD] --Watch before starting Cold Steel 2, this is essentially cut content for CS1.
The Remote Town of Aster [DRAMA CD] -- Watch after Cold Steel 2
CS2 NEW GAME + THE BLACK RECORDS -- Hidden NG+ scene after collecting all the Black Records. (so you won't be confused in CS3 if you didnt have time to play through this again)
The Northern War [ANIME] -- Takes place between CS2 and 3. Out on Crunchy Roll. This came out after CS4 so its not necessary to watch right after CS2.
CS4 Secret Scene After the True Ending Credits -- After Clearing CS4's True Ending reload the last save and after you watch the credits again their is a secret scene.
-TRAILS INTO REVERIE-
Trails into Reverie Post Game -- Just a reminder after the you beat the main story its not over, the Reverie Corridor remains.
-TOKYO XANADU-
Tokyo Xanadu ex+ -- Lets just say their seems to be some connections between this game and Trails especially Cold Steel.