We finally get a conclusion on the Lunar Leviathan of the sea! It is now up to you to catch the beautiful Moonfin fishes using Kujirai’s help.
Teleport to the waypoint near the entrance to the city and talk to Kujirai. She will tell you to go to the Kannazuka beach in Inazuma. Use the northern teleport in Tatarasuna and glide down to the beach. Adjust your time to 19:00 to 22:00 in the night to activate the quest.
Kujirai will give you the Moonstringer Fishing Rod and 20 Glowgrass Bait and asks you to catch all the Moonfin fishes in the area. Use the bait on the moonfin and be patient. You need to catch two Moonfin consecutively within the time limit.
If you catch more than three Moonfin fishes, the rest will be set free. You also need to stay in the tension zone for at least 3 seconds. Doing so will complete all three challenges and give you a total of 60 Primogems, 60,000 Mora, 3 Hero’s Wit, 6 Mystic Enhancement Ore, and 4 Sanctifying Oils. Completing the quest also unlocks the Moonstringer Fishing Rod and Moonfin Fish.