TV-Series
Description
In the anime Igano Kabamaru, the character known in the original Japanese version as Hayate Kirino is named Guillaume in the French adaptation. He holds a crucial and deeply personal role in the protagonist's life. Guillaume is introduced as the cherished childhood friend and adoptive brother of the main character, Benjamin (whose original name is Kabamaru Igano). The two boys were orphaned at a young age and were taken in by Benjamin's grandfather, Saizo, who raised them together in the remote mountains of the Iga province, training them rigorously in the art of the ninja.

Personality wise, Guillaume is presented as a complex figure marked by a deep internal conflict. While flashbacks reveal a sweet and caring boy who shared a strong bond with Benjamin, helping each other endure the pain and hardship of their upbringing, the character seen in the present is much colder and more aloof. He is portrayed as a rival who has consciously chosen to reject his past and the brotherly bond they once shared. In a painful confrontation, he tells Benjamin that he only used him to escape from their grandfather and their life in the mountains, urging him to forget their friendship and stay in his new life in the city.

Guillaume's primary motivation stems from a desire to completely sever ties with his past and forge his own path, separate from the ninja traditions and the emotional connections that defined his childhood. Unlike Benjamin, who is eager to adapt to a new urban life and form new relationships, Guillaume seems determined to face the future alone, even if it means becoming an antagonist. In the story, he aligns himself with the rival Ogyoku Academy, putting him in direct opposition to Benjamin and his new friends at Kin'gyoku School. His role is that of a tragic rival and a living reminder of Benjamin's past, forcing the protagonist to confront his own origins and the meaning of their shared history.

The central and most defining relationship of Guillaume is, without a doubt, his bond with Benjamin. Their connection is the emotional core of the rivalry that drives much of the later conflict. The story complicates matters significantly when it is revealed that Guillaume was responsible for kidnapping Mai, the girl Benjamin has fallen in love with, escalating their personal struggle to a critical point. This act forces a final, emotional confrontation between the two former friends.

Throughout the series, Guillaume undergoes a significant development. His journey is one of reconciliation. After a fierce battle with Benjamin, the truth of their past is fully confronted. At the climax of the story, their grandfather Saizo, who had faked his own death, reappears. This event provides the catalyst for healing the rift between the two boys. Having resolved their conflict, Guillaume and Benjamin reconcile and make the decision to return together with Saizo to the mountains, where they will continue their ninja training as brothers once more. This ending suggests that while Guillaume tried to reject his past, his fundamental bond with Benjamin was ultimately stronger.

In terms of notable abilities, Guillaume, having been trained alongside Benjamin by the same strict master, is a highly skilled and formidable ninja. He possesses physical prowess comparable to the protagonist, making him a truly worthy rival. His training has granted him superhuman speed, agility, and strength, as well as mastery over traditional ninja techniques. The fact that he was raised as Benjamin's equal in the mountains makes him one of the few characters who can challenge the protagonist on an even footing, a point that is emphasized during their final fight where their skills are shown to be nearly perfectly matched.