- This wise and educated monarch rules Sana from the capital of Tonfon. He succeeded the warlike Emperor Ko after a bloody civil war, uniting and bringing peace to his war-torn country.
Some point prior to the timeline of Golden Sun: Dark Dawn, Sana's founder and first leader, the warlike Emperor Ko, died. After Ko's death, a civil war broke out, pitting Ko's intended successor, King Wo, against Unan. Ultimately Unan was successful, though the victory was not without loss. The Sanan colony of Morgal had taken the civil war as an opportunity to launch a successful revolt. In the battle, Unan's brother, Lord Kuan, was killed and Lord Kuan's children went missing. Unan's reign brought much-needed peace to the region, though he and Lady Hinechou grieve for the loss of their loved ones.
Later, Matthew and his group meet with Unan to discuss the Grave Eclipse that is ravaging much of Angara. Unan's own country is unaffected by the eclipse, and the group has heard of his wisdom. The group of Adepts reveal that Ryu Kou and Hou Ju had been alive prior to the Eclipse. Unan then offers the group some of his knowledge about the events. At an unknown point prior to Lord Kuan's death, he had visited his brother in Morgal, and thus had learned about Luna Tower, the Eclipse, and the methods by which to halt the calamity. Unan tells the group of the Umbra Map, an ancient map that marks the locations of the Umbra Gear, which is necessary to stop the Eclipse, but notes that it is not in his possession. Ryu Kou inherited the map from his father, and so the Adepts decide to try to locate him. Before they leave, Unan opens his personal vault up to the group, insisting that they use the treasures inside to help stop the Eclipse.
Matthew and his group successfully retrieve Hou Ju and Ryu Kou, and return them to Sana. After a joyful reunion, Unan asks for a private meeting with Matthew's group. He explains that a man called Arcanus had given him a Red Orb to pass on to the group, as it would assist in their efforts to stop the Eclipse. He is somewhat surprised to discover from the Adepts that Arcanus had a hand in creating the Grave Eclipse. He then explains that the Red Orb, as well as the Blue Orb that the party already possesses, is needed to access the Apollo Lens. In conjunction with a third orb, the two orbs help open a gate at the Endless Wall, and later help raise the Apollo Lens out of the ground. Unan is able to give a vague description as to where the third orb is, saying that the Red and Blue Orbs are needed for reveal it. A prophecy from Himi helps to confirm this knowledge, and also give a specific location as to where the Orb may be. Unan wishes the party well as they leave, but remains puzzled over Arcanus's ambitions.
- If the player chooses to rescue Hou Ju and Ryu Kou before visiting Unan, he will make an error in his quote after opening the secret doorway in his study. He will say something along the lines of "I do have one favour to ask of you. If, in your travels, you find my niece and nephew, please return them to my sister-in-law, Hinechou". It is as if the player did things out-of-order.