Now, I'm sure most of you know about it but there are still newcomers and they have to be informed. He's/You're Beautiful is about this young girl, who was a former sister, but because of her twin brother (who suffered some intervention in America) she has to take his place as an idol. So, Go Mi Nyu becomes Go Mi Nam in the band A.N.Jell. The three other members are Hwan Tae Kyung (Jang Keun Suk), Kang Shin Woo (Jung Yong Hwa) and Jeremy (Lee Hongki). At first, Tae Kyung doesn't like Mi Nam and makes his (well, her) life a living hell. However, he discovers that Mi Nam is a girl and, even though he treats to tell, he doesn't and helps her keep the secret. Of course, there are other problems coming the way and eventually, everyone in the band finds out the truth...
I was amazed how, throughout the whole series, Keun Suk rarely smiles. I couldn't imagine he has such a cute smile! Anyway, the characters fit excellently with the actors. Yong Hwa is a talented young man and because I was a little sad when I saw how Shin Woo didn't get the girl (because they all start to like Mi Nyu at some point) even though he did so much for her, when I heard about Heartstrings I got really excited. Actually, these two dramas complete, somehow, each other. Wise was the one who decided to make a series with Yong Hwa and Shine Hye right after He's/You're Beautiful.
One thing I usually am very critic about is music and the OST. This drama has the best OST I've heard until now. The songs really get you into that sad or happy atmosphere and help you understand and feel more the supposed feelings the situation has.
So, in the end, whoever doesn't know about these two dramas, I advice you to watch He's/You're Beautiful and after that, Heartstrings. You'll see that it does make sense. :D