Kegon (華厳) was the seventh son of the Water Daimyo during the end of the Warring States Era. Kegon, though the youngest of seven children, was favored by his father due to being the son of the only wife that he loved. This led to many assassination attempts by his elder brothers - each failing. Due to his survival of many attempts to end his life, Kegon's father deemed him very lucky. This led him to decide to make Kegon the next Water Daimyo after his passing much to his other son's chagrin. This decision, however, put Kegon's life in danget but also led him to meet the one who would hold his heart - Izayoi.

After the news of Kegon becoming the next in line reached his brothers, they all joined together to hire a ninja to assassinate their brother - this time aiming at using a skilled ninja to execute their plan. Fearing for his life, Kegon petitioned for the visiting nomads- the Kaguya clan - to assist in protecting them. No longer interested in fighting, Kaguya Izayoi denied the clan's services. Kegon, more curious about Izayoi than preserving his life, attempted to court her instead - much to Izayoi's disatisfaction. However, urged on by the clan's elders to have her preserve the Kaguya line, Izayoi found herself in his company. Although still emotionally wounded by her previous relationship with Uchiha Madara, Izayoi found a silent comfort in Kegon's gentle personality. She later came to appreciate his goals and ambitions for peace, just as she did for her own people. Despite still pained by her previous relationship, Izayoi agreed, along with the clan elders, that persuing a romantic relationship with Kegon would benefit her clan and even her future children.