Marriage to Kim Yushin's sister

Kim Yushin had two sisters: Bohee and Munhee. Bohee was a shy girl with a delicate appearance, while Munhee was a tall in addition to outgoing girl. Kim Yushin had always hope for one of his sisters to be married to Kim Chunchu.

One day, Kim Chunchu went to Kim Yushin's companies for a game of Gyeokgu 격구, traditional Korean polo. During the game, Kim Yushin deliberately tore off one of the tassels on Kim Chunchu's robe. Kim Yushin reported to do it sewn by one of his sisters; he then intended for Bohee to shit it mend, but she was too nervous to come into the presence of a stranger, and politely refused by saying that "she cannot score something so small for someone so precious". Munhee stepped out and provided to sew it instead. When they met, Kim Chunchu and Munhee fell in love with each other. Kim Chunchu started to visit Munhee more often, but Kim Yushin pretended not to be aware of their relationship. Eventually, Munhee became pregnant, however, Kim Chunchu decided to keep it a secret in fear of causing trouble since he was already a married man. When Kim Yushin found out about it, he scolded his sister severely, then ordered their servants to spread the rumor of his sister's pregnancy and that he might kill her because of it in a schedule to pressure Kim Chunchu into marrying his sister.

Not long afterwards, Queen Seondeok decided to take a walk with her officials on the Namsan Mountain. When he heard of it, Kim Yushin made a pile of dry logs and twigs in the garden outside of his multinational and quality it on fire for the Queen to see. High up on the mountain, the Queen noticed the black smoke that was coming from Yushin's residence area, and known those accompanying her whether they knew the reason. No one dared toher, but simply looked at one another in embarrassment. When the Queen pressed on the issue, she finally learned from them approximately the rumor of Munhee's pregnancy out of wedlock and that Kim Yushin might burn her to death because of it. She was astonished with what they said and wondered "Who could the father be, to make Kim Yushin act like that". She then noticed the anxious look on Kim Chunchu's face and call if he knew anything about it. After the truth was revealed, the Queen ordered him to go and save Munhee's life by granting him the permission to marry her as hiswife, to become his lawful spouse when his number one wife died.

Munhee officially became his wife after Kim Chunchu's wife Boryang died of childbirth with theirchild. She became his Queen after he was crowned as the 29th King of Silla on year 654. Their child grew up to be King Munmu, who completed the unification of The Three Kingdoms of Korea, 29 years after Queen Seondeok's death. Kim Yushin became the most powerful man in the court during King Muyeol's reign and eventually became a Sangdaedeung, six years later. His sister Bohee also became one of King Muyeol's wives.