Kiiro

was a freelance shinobi.

Background
Kiiro was born into a family of bee users. By tradition, only the firstborn, Kodaka, was taught how to control the bees, and it was the responsibility of Kiiro, as the secondborn, to protect Kodaka. Kiiro resented this responsibility, believing he could make better use of the bees and that giving his life to protect Kodaka, which was expected of him, would be a waste of his talents. Kiiro did not hide these feelings from Kodaka.

After their parents died, it fell to Kodaka and Kiiro to support their much younger brothers, Ōmitsu and Komitsu. Their family's tradition of harvesting honey didn't earn enough for the four of them, so Kiiro convinced Kodaka to start taking freelance work from hidden villages. Whereas Kodaka only wanted to earn enough money to return to Ōmitsu and Komitsu, Kiiro wanted fame and glory. He devised a routine that he and Kodaka could use to kill targets after only two bee stings, which proved very successful on missions. The two eventually gained the attention of Kirigakure, who frequently employed them and provided Kiiro the recognition he craved.

Kodaka and Kiiro were eventually attached to a team of Kiri hunter-nin assigned to capture Kisame Hoshigaki of Akatsuki. Upon finding Kisame, the hunter-nin were quickly killed. While Kisame was preoccupied with that, Kiiro attacked him with Water Release: Water Dragon Bullet Technique, creating an opportunity for Kodaka to sting Kisame once with his bees. Kiiro tried to create an opening for a second sting, but was confronted by Kisame's partner, Itachi Uchiha, who knocked Kiiro out with Tsukuyomi. When he regained consciousness, he discovered that Kodaka had taken him and ran away. He cursed Kodaka for cowardice and said he hated him. Kodaka ignored this and, doubting they could defeat Kisame and Itachi, wanted to return to Ōmitsu and Komitsu, as they'd made enough money from their previous missions. Kiiro refused, too motivated by the fame they could achieve by killing Kisame, and insisted they try again once he recovered.

Itachi and Kisame eventually tracked them down. Kiiro tried to create an opening for Kodaka's bees to sting Kisame a second time, but he was still weak from the earlier Tsukuyomi; what little he could do was easily blocked and Kodaka's bees couldn't sting Kisame without his help. Itachi then tried to kill Kiiro with a Great Fireball Technique, but Kodaka leapt in front of the attack and used himself as a shield, becoming badly burned in the process. With his waning strength, Kodaka had his bees attack Kiiro, numbing him so badly that he couldn't move or speak. He then pretended to carry out a murder-suicide, first pretending to stab Kiiro in the heart - unseen due to all the bees - and then actually stabbing himself. Kodaka's bees grew agitated by his death, forcing Kisame and Itachi to flee the area.

Even though he couldn't move, Kiiro could still hear what Kodaka said as part of his ruse: how frustrated he was with Kiiro's jealousy, his rudeness, and for forcing him into shinobi work; although beekeeping was difficult, it was something safe that the family could do together. Yet despite it all, he loved Kiiro, just like Ōmitsu and Komitsu did. Kiiro felt responsible for Kodaka's death, because if he'd listened to Kodaka and escaped when they had the chance, Kodaka would still be alive. He also wondered why Itachi allowed him to live, as his Sharingan would doubtlessly have let him know that Kodaka had only pretended to kill him.

Kiiro returned to Ōmitsu and Komitsu and told them about Kodaka's death. Despite Kiiro's repeated attempts to explain what happened to Kodaka, they continued to misunderstand Akatsuki and its members as being responsible. Before Kodaka died, he transferred his bees to Kiiro. Kiiro used the bees to travel around with Ōmitsu and Komitsu, selling honey to make a living, like Kodaka always wanted. When they found a field of rare white flowers in the Valley of Lies, Kiiro cultivated the flowers until the field was large enough to support them. They settled in the area and Kiiro eventually met Kanyū, who he married and had a son with.

Akatsuki Hiden: Evil Flowers in Full Bloom
Kiiro finds Ōmitsu and Komitsu playing among the flowers. Because the flowers are their livelihood, he lectures them once again not to do this. They apologize and introduce him to Sasuke Uchiha, who Kiiro initially mistakes for Itachi before realizing that Itachi would be dead by now. Ōmitsu explains that Sasuke saved Komitsu from falling off a cliff. Kiiro thanks Sasuke and sends Ōmitsu and Komitsu home to retrieve some medicinal honey to give to Sasuke as a gift.

While they're gone, Sasuke asks how Kiiro knows Itachi, and Kiiro briefly details when he and Kodaka met Itachi and Kisame. Now that he's met Sasuke, Kiiro believes he knows why Itachi spared him all those years ago: Itachi, like Kodaka, had a younger brother. Ōmitsu and Komitsu soon return with the medicinal honey; they also bring Kiiro's infant son, who they thought was lonely. Kiiro holds his son and gives Sasuke the honey. As Sasuke departs, Kiiro shouts to him, asking if his brother was kind like Kodaka was. Sasuke replies, "Yeah!"

Trivia

 * means "yellow" or "yellow colour".