|Novel|| Moribito: Guardian of the Spirit (mentioned)|
Moribito II: Guardian of the Darkness (mentioned)
When Balsa was five years old, Balsa's mother died, leaving Karuna to care for his daughter with the effort of two parents. In contrast to the reserved Jiguro, Karuna was described as a man who talked and laughed a lot, as well as a person with keen intelligence and dexterity rather than possessing any combat abilities. Though he was often away from home because of his position of the chief royal physician, Karuna was a loving father and Balsa was happy at home. In Karuna's absence, Balsa was partially cared for by his younger sister, Yuka.
Because the king was often sickly, his younger brother Crown Prince Rogsam eventually coerced Karuna into gradually poisoning the king. With the threat that Balsa would be killed if he refused, Karuna complied, but knew that as soon as the king was dead, both he and Balsa would be killed by Rogsam for knowing the truth behind the king's death. In hopes of at least saving his daughter, Karuna asked Jiguro, his most trusted friend in the palace, to protect Balsa. Jiguro had refused at the time, but Karuna had returned home to find that Jiguro had taken Balsa and fled after Rogsam's men attempted to kill her earlier in the day.
To protect Yuka from Rogsam's men, Karuna told her that Balsa had died in an accident and her body could not be recovered. Several days later, he was murdered by Rogsam's men; Rogsam would tell Yuka and the Yonsa clan that Karuna had been killed by thieves. Balsa would not learn of her father's death until she arrived in New Yogo, where a Kanbalese migrant worker informed Jiguro of what had transpired.