Fishing is the best part of any game hands down. I rest my case.

But anyways here is a basic 100% fishing guide for Trails of Reverie, including upgrades, fish, locations, and drops. The fishing in the game isn't too tricky if you keep an eye out but the split chapters might make it hard to catch all the fish in your run. Important things to keep in mind is that any of the fish in the Crossbell area can be caught right before the final dungeon while in the prep phase, notes are shared amongst teams once they join they crew, and that any of the fish caught from the Reverie Garden can be caught at any time regardless of progress.

That's all the info I can think of but if there is anything to be added let me know!
Happy Fishing!

• Delicious Bait -Act 1, Lloyd Route, Received from event at Crosbell Fishing Association-
  
• Custom Handle -Act 1, Lloyd Route, Purchase from Fishing Association-
  
• Titanium Hook -Act 1, Lloyd Route, Received from event at Plover Goods in Ymir-
  
• Agilatarin Leader -Act 1, Rean Route, Purchased from Plover Goods in Ymir-
  
• Crown String -Act 2, Lloyd Route, Purchase from Jake's General Goods in Amorica Village-
  
• Lakelord ATD -Act 2, Rean Route, Purchase from Lakelord Company in Leica District, Heimdallr-
  
• Custom Spool -Act 3, C's Route, Received from event-
  
• RF Bearing Zero -Act 3, C's Route, Purchase from Fishing Association in Crossbell-
  
• Goldia Rod -Act 3, C's Route, treasure chest in Rosenberg Doll Workshop-
  
• Zemuria Hook -Complete Master mission: catch 12 different species of fish-
  
• Bombing Dash V -Complete Master mission: catch 18 different species of fish-
  
• High End Spool -Complete Master mission: catch 24 different species of fish-

Congrats!