With all the freebies on Thursday it felt like Nintendo honestly didn't want me to find time to return to my fishing sessions and catch that final piece for my collection, but I did it anyway and thus finally completed Majora's Mask 3D again.
The strategy to catch the Great Fairy Fish was pretty much the same as last time. Go do a lot fishing at the Ocean Fishing Hole during the first two days and then save your game at the Dawn of the Final Day, so you can reset, if you didn't have any luck. Now, keep using the door at the Ocean Fishing Hole with the Great Fairy's Mask on, until the hair glimmers. Then check for the Great Fairy Fish (you really have to go close to the crystal cave as Zora Link) and repeat, if it's not there.
Any small Fairy Fish then will do, it doesn't matter much, where they are. You don't have to push your luck and try to find a combination, where the small one spawns right in front of the big one. You can just lure him there and use your Fishing Rod to move him in the right spot.
Finally, reeling the Great Fairy Fish in takes a long time with the incredibly weak Young Link, for me it took 5 ingame hours with the Inverted Song of Time in tact. So, you probably don't want to try this after the final midnight, or else the moon might crash on your during the process. Play it safe.
Luckily with such a big fish the pillars in the water don't seem to be a problem. With smaller fish like the Ambrosial Amberjack the borders can really get in the way and make it hard to reel them in at the end. Landing fish on the shore is much easier. But this doesn't seem to be a problem with the really large fish, which just pop on the ground easily.
Here are my records of my second fishing playthrough (the values in parenthesis are from the German translation):
- Termina Bass: 13cm (60cm)
- Termina Loach: 22cm (79cm)
- Groovy Carp: 5cm (38cm)
- Sweet Ranchfish: 5cm (39cm)
- Fragrant Reekfish: 10cm (52cm)
- Mooranha: 5cm (38cm)
- Postal Salmon: 34cm (97cm)
- Cuccofish: 6cm (40cm)
- Ancient Fish: 107cm (172cm)
- Ferocious Pirarucu: 174cm (220cm)
- Colossal Catfish: 117cm (180cm)
- Lord Chapu-Chapu: 357cm (315cm)
- Termina Seabass: 32cm (95cm)
- Goodta Goby: 6cm (42cm)
- Ambrosial Amberjack: 39cm (104cm)
- Bashful Angler: 47cm (114cm)
- Dancing Sea Bream: 21cm (76cm)
- Fairy Fish: 11cm (56cm)
- Ninja Flounder: 20cm (75cm)
- Skullfish: 34cm (97cm)
- Nuptuna: 97cm (164cm)
- Grand Swordfish: 184cm (226cm)
- Savage Shark: 223cm (249cm)
- Great Fairy Fish: 342cm (308cm)
It took me a total of three cycles (about 6 real hours) to replay the fishing minigame and it overall was quite enjoyable. I probably wouldn't do it again anytime soon and rather try to improve the size records for each fish, but if you're only aiming at catching one fish per type to get the entries, it can be done pretty quickly.