|“||Try to run as much as you like. I'll never let you go.||”|
—Volume 006, Chapter 27
Irada Ki Aku is the Crown Prince of the Empire of Sand. While his formal name is Irada Ki Aku, most of his retainers and subjects call him Taishi.
Taishi is noted to have striking blue-pine eyes, which is one of the first things people notice about him. He is also remarked upon to speak rather eloquently.
In Taishi's first appearance, he is mentioned by Neil to have a reputation of a ruthlessly pragmatic man, who would not stand for any stain of the honour or name of his Empire. If another country tried to use unflattering methods to damage the Sand Empire's reputation he would retaliate with all his power. From that intensity, he earns the nickname "The Prince of Thunder."
As we learn more about Taishi, he is also shown to have a humble and simple character, disliking doing things in a roundabout manner, preferring to deal with things personally and with pomp.
His dislikes frivolous, lavish and wasteful things, preferring modest accommodations and talk.
He is also a kind and gentle prince who cares about the well-being of his subjects and listen to his subjects' plight. Under his management, he has helped his Empire improved greatly despite its improvise state. He also is known for being incredibly moral and responsible, which is evident when he admits to trying to kidnap Nike and keeping her in his kingdom to Livius even though he knew that he could be severely punished for having done so.
During his youth Taishi was scolded for interacting with the common people. He was taught by his mother that he was of royal blood and that others were beneath him. He was close to his his sister Amarudina who was treated as a 'demon child' for constantly disobeying their mother.
Everything changed when the drought occurred and a plague spread claiming the life of his sister. The Queen refused to allow the castle's water reserves to be accessed by the people claiming they were of royal blood and could not contaminate themselves by mixing with commoners. Though he was young he usurped the Queen's power and released the water stores.
He is a much beloved Prince in his empire and genuinely cares about the well-being of his subjects. He came to the Sun Kingdom in order to studied the Sun Kingdom's irrigation facilities and to request aid for their water supply because the oasis of his land has been drying up for the past few years and towns have been swallowed up by sand.
Additionally, rain in the Land of Sand has begun to fall less and less. To his people, water is like blood and rain is like a "miracle," which was why he looked so devastated when Nike made it rain as a spectacle. When Nike realizes how much the spectacle and the luxury she showered him with made him feel pained when his own people were suffering, she apologizes and decides to go to the Land of Sand with him and Falaha to help his people.
Tashi eventually falls in love with Nike and later, attempts to kidnap her not only for his empire but because of his own personal feelings towards her. Although he was willing to accept any punishment from Livius for doing so, Nike convinces Livius not to punish him or his empire.
- Prince Taishi has multiple retainers which include: Falaha, Uluma, Hasan who enjoys food, Aadi who can't get up in the morning and Yasima who cries easily.