The Secret Romantic Guesthouse

=> 3 male leads and one female lead sageuk drama
=> According to Secret Romantic Guesthouse's plot summary, the four friends will work together. It was basically the plot of Sunkgyunkwan Scandal in the latter episodes.
=> The male leads in Secret Romantic Guesthouse and all the main characters in Sungkyunkwn Scandals are young scholars.

859 AD. The once-great Tang Dynasty is now declining. Numerous rebel groups have formed, the largest of which is the House of Flying Daggers, based in Feng Tian county. They steal from the rich and give to the poor, gaining the support of people. The local deputies have managed to kill their former leader, but the rebel group only becomes stronger, due to a mysterious new one. Jin and Liu, two police captains, are ordered to kill the new leader within ten days.

The series tells the story of a man-turned-immortal, Bulgasal, who wants revenge from a woman with a mysterious past and present, who he deems responsible for his immortality and miseries from the past 600 years, hoping to free himself from his curse.

When a total eclipse of the sun takes place, Go Ha Jin is transported back in time to the start of the Goryeo Dynasty of Korea during King Taejo's rule. She wakes up in the body of the 16-year-old Hae Soo and finds herself living in the house of the 8th Prince Wang Wook, who is married to Hae Soo's cousin. She soon befriends several of the princes and meets the ostracized 4th Prince, Wang So. Although knowing she should not get involved in palace intrigues over the succession to the throne, she inadvertently becomes a pawn in the struggle, as several of the Princes fall in love with her.

In 18th-century Korea, Prince Yi San is a perfectionist haunted by his father's murder. He's set to inherit the throne once his cruel grandfather, the current king, passes away. Despite the emotional scars left by his father's death, Yi San aspires to be a benevolent ruler who reforms the kingdom's laws. At court, he encounters Sung Deok Im, a spirited and intelligent young woman. While Yi San falls in love and proposes she become his concubine, Sung Deok Im grapples with the restrictions and responsibilities that come with royal life. However, as their love deepens, she begins to see the potential to bring positive change to the troubled realm through their union.

In his early years, Oda Nobunaga picked up the nickname of "The Fool of Owari" due to his bizarre behavior. He later married Nohime, but their relationship was not very good. Their marriage came about as a political marriage between hostile neighboring regions. Oda Nobunaga accepted Nohime as his wife with an arrogant, authoritative attitude. Meanwhile, Nohime has an unabashed attitude and easily clashes with her husband. They are like oil and water.

One day, Oda Nobunaga’s enemy Imagawa Yoshimoto attacks Owari with his vast army.

Oda Nobunaga is devastated by the overwhelming gap in military strength, but Nohime encourages Oda Nobunaga to not despair and fight against his rival. Oda Nobunaga and Nohime draw up a tactical plan to take on the much larger army. They soon make plans to unify the entire country, which has never been successfully done.

Both are historical and centered around three MLs and one FL. At least one of the MLs seems to have/has secrets about his past. Both dramas have a similar tone.

Zhu Yan Zhi, disguised as a man, seeks to learn martial arts with an elite clan. Once she begins her intense training, Zhu finds herself at odds with her trainer and superior, Liang.

In the late Joseon dynasty, counterfeits were circulating around. Detective Ahn of Left Security Station and a passionate newcomer, Nam Sun, try to trace the source of the counterfeiting. They chase the Secretary of National Security and his man 'Sad Eye' as suspects. A predestined battle between the best woman detective in Joseon, Nam Sun, and a mysterious assassin 'Sad Eye' is unfolded. A magnificent, chivalric film that showcases Lee's style

All the gods will be leaving before the last rain of doomsday. However, an ordinary human girl unexpectedly puts a dent in their plans to retreat thus causing the world to move towards the unknown. Based on the animistic mythology of the Amis tribe, the gods are no longer willing to bless the land that is plagued with environmental issues. One by one, the gods depart the world they once loved. A human girl discovers that the opportunity to reverse her destiny lies within herself and her guardian. Before the final day of judgment, a love story between human and god unfolds.

• Both are Historical Fictions
• Both have a confident and kind female leads
• Both have a protective and skilled swordsman male leads
• Both male leads have a hidden identities
• Both female leads live a life atypical from the Joseon noblewoman norm because of a family disaster.
• Both are slow, sweet romances
• Both work to help secure the royal family with investigation(s)
• Both have a happy ending

Episodic saga from the first half of the 20th century follows Hero Hua from an ill-omened June day in his youth to a showdown 17 years later with a disaffected member of his martial-arts school, a Japanese named Invincible. Tensions between Chinese and Japanese, plus U.S. racism, mark the tale. Hero marries Jade, leaves her in China when he goes to America as an indentured servant, rebels against cruel labor conditions, and is joined by her in New York City where she has twins. Jump ahead 16 years: their son Sword comes to New York looking for his father. There, Sword hears many stories of his father, which we see in flashbacks, and the stage is set for the battle with Invincible.

Wang Won’s father is the king of Goryeo while his mother is the Yuan emperor’s daughter. He was born with many gifts as he has good looks, the wisdom of a snake, and a magnetic personality that draws people to him. But behind his gentle, virtuous demeanor, he has ambitions to conquer other lands. He has a faithful friend named Rin, who is a royal cousin and comrade with the same ambitions as he does. Then Wang Won has an encounter with a young woman named, San. San was someone that he recalled having met when he was a child and was lodged in his mind ever since. Wang Won sees how bright and confident San is and befriends her as well. But this friendship plants the seeds of tragedy. San’s beauty mesmerizes both Won and Rin and their seemingly strong bond start to fray over one woman

We have one women lead surrounded by three other men lead, one of them is Jung Gun Joo and the place background is same, guesthouse.

Sinilarities:
- Both are historical dramas with comical elements.
- FL in both dramas is surrounded by multiple MLs with whom she forms a friendship.
- MLs have a hidden past / agenda.
- There is a love triangle in both but in H it's more present than in TSRG