Ryuuga Family Arc is one of many story arcs of Yuragi-sou no Yuuna-san series. This arc illustrates Ryuuga Genshiro of the Ryuuga Clan who "proposes" his marriage to Yunna and makes her as his bride against her will. To rescue Yuuna from Genshiro's grasp and preventing the marriage, Kogarashi and Sagiri have to infiltrate into the Dragon Grace Castle and confront the Dragon God himself and his aide/adoptive sister Oboro.
Dragon Lord's Search for Harem
Operation Rescuing Yuuna
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Kogarashi's Wrath and Genshiro's Defeat
Hearing enough of Genshiro's gloating as well as Yuuna's sadness, Kogarashi provokes the Dragon Lord by lying about his "improved" relationship with Yuuna by bathing together, much to the shock of Yuuna and Sagari. Kogarashi's lie infuriates Genshiro so much to the point kicking Kogarashi hard enough that sending him lying to the cavern roof. Even so, Dragon Lord isn't done with Kogarashi as he yearns to torture the mortal more for his "insolence".
Miraculously, Kogarashi survives the attack and demands Genshiro to either release Yuuna and Sagiri now or he will go to get them by force. His demand, however, is ridiculed by the fishmen, Oboro and especially Genshiro as they belittle him for a mere mortal with Genshiro himself adding insult to Kogarashi that he will not stop his marriage with his "brides". Still, Kogarashi doesn't care and immediately punches Genshiro's guts that hurt him so much that not only sends him flying but also destroys part of the castle and even shatters the protection barrier himself. This phenomenal has garnered everyone's bewilderment and confusion, specifically Yuuna, Sagiri and Oboro who are too stunned to see what had happened. Kogarashi then reveals that his unnatural power was the result of his rigorous training under a master who possessed him prior, as well as his creed of not beating a woman.
Oboro the Female Guardian
Just as Kogarashi demands the release of Yuuna and Sagiri, the fishmen guards urges Oboro to escape but she decides to stay behind and face Kogarashi herself while orders them to recover Genshiro. Oboro begins the brawl by slashing Kogarashi from behind that barely even fazes him.
Oboro's exploitation of Kogarashi's "weakness" renders him defenseless against Oboro's barrages of attacks, all the while hearing Oboro's blaming him for "ruining" the Ryuuga Clan's plan of having stronger kin. As Yuuna worries about Kogarashi, Sagiri reassures her friend that he will be fine but even she herself is envious about Kogarashi's unnatural strength. Just as Oboro delivers her fatal blow to Kogarashi, the fight eventually stops when reinforcements (Nonko and Yaya but not Chitose) arrive and Nonko holds Oboro's left blade effortlessly.
Despite the outcome, Oboro still has all of female opponents to be married with Genshiro.
Oboro's Entry in the Yuragi Inn 
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- The Black Dragon Clan is introduced as the main antagonists in this arc. According to Sagiri herself, until Kogarashi do the impossible by punching Genshiro's guts that sends him flying.
- Genshiro is introduced as the Lord of his clan, the Ryuuga Clan, as well as a prominent rival to Kogarashi himself due to his illustrious status as Godhood which prompts him belittling a mortal, only to be beaten easily by the said mortal's punch to his gut. It's until the Ryuuga Family Rematch Arc where he eventually confronts Kogarashi for a rematch, albeit for a different reason.
- Oboro is introduced as the devoted protector to Genshiro, the Head of the Ryuuga Clan who happens to be her half-brother through different mothers.
- Kogarashi's supernatural feats of endurance and strength bewilders almost everyone especially after witnessing his surprising victory against the Dragon God, including Sagiri and Yuuna. This alone prompts everyone (which includes Chisaki) Eventually, it takes several arcs (especially Hiougi Estate Arc[Notes 1] and Makyouin Ouga Arc[Notes 2]) to explain the origins of his supernatural feats.
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