Autumn's Concerto

Shirai Yui has decided to take a new job as a secretary at the law firm of her childhood friends, the Kami brothers. Yui has feelings for her older brother, Soichi, but when they meet again for the first time in 18 years, she is confused to find that Soichi has become a cool, unsmiling man. Meanwhile, her younger brother, Yushiro, has always loved Yui, but has not been able to express his feelings. And Soichi has been unable to express his love for Yui due to a childhood trauma. The love stories of Yui, who loves Soichi, Yushiro, who loves Yui, and Soichi, who is jealous of Yui's close friend, all intertwine.

In QoT the female are the one having brain tumor also amnesia
Also rich female lead

While in AC the male are the one who have it
Both also dealing about marriage problem
If the rumor are true about the script from 2010
Then it was around 1 year after AC released

Takuya, a budding hockey player, becomes captivated by Sakura, a young girl practicing figure skating. Sakura's coach, Arakawa, notices Takuya mimicking the figure skating moves, wearing his hockey skate and falling time and time again.

Seeing Takuya's persistence, Arakawa decides to take him under his wings. At Arakawa's proposal, eventually, Takuya and Sakura begin practicing ice dancing as a pair.

Both stories feature a young single mother who live in a small town. But how each story story plays out they differ from each other.

Ayaka, who works at the bridal department at a hotel, has a beauty that everyone recognizes, yet her personality is the worst. Everyone calls her a "wicked woman" after the way she wraps numerous men around her finger. The one who sets his eyes on her is the hotel's new executive Togo, who is the son of a very powerful person of the town. What are the orders that this King-like man requests of her!?

In both dramas, they fall in love with the main character and are forced to break up. After the breakup, the main character finds out that she is pregnant. over time they will meet and everything will turn out well the family will be together.

In both series there are lovers that are separated then are reunited.
There are other similarities that are spoilers for both series.

Both have love triangle and a the male lead has lost memory.

Hyun Jae is only 19-years-old, but he has a terminal illness and he does not have much time left to live. He leaves the hospital and goes back to high school. There, he falls in love with Soo Min.