Hagie is trying to make a profit off of the green crystal he found buried at the Construction Site.
Quest Location
Talk to Hagie in Tarrey Town to start the quest. You may need to go to Jochi-ihiga Shrine first to make a beam of light shine between the empty shrine and the shrine crystal next to Hagie.
How to Complete the Quest
It is recommended to complete the quest Mattison's Independence before you do this quest. That way, Hagie will stop charging a fee to use the railcar.
Ask Hagie to give you a lower price until his wife intervenes. Then buy the crystal for 50 rupees.
This allows you to open Jochi-ihiga Shrine.
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