A young, independent nobelwoman's life changes radically when her whole family is murdered and she is accused of poisoning them.  She goes into hiding, hoping to find out the truth behind their deaths.  Based on her father's final words to her, she seeks out the Crown Prince who was her father's student.  Vowing to keep her safe for the sake of his dead mentor, the Crown Prince allows her to disguise herself as a Eunuch in the service of the Prince.  Now together, the pair are working to find the true killers and clear her name.

Jeon So Nee as Min Jae Yi

Min Jae Yi was engaged and very happy at the prospect of her new role and her handsome future husband.  But when her family is all suddenly poisoned by a dinner she served them, she finds herself alone and wanted for murder. Her father's final words to her were to save the Crown Prince, so she sets out to find him.  But even after meeting him, he isn't sure she can be trusted and she can't just waltz into the palace as a wanted noblewoman.  So she disguises herself as a eunuch for the Crown Prince.  While he still isn't sure about her, her determination wins the Crown Prince's approval.  As she spends time working with him, both as his eunuch and as his friend, they find that the case of the Prince's mysterious curse and the death of her family are definitely connected.  

Min Jae Yi is independent and strong willed.  She spent her youth posing as her brother, while she investigated dead bodies and suspicious deaths for her father.  When she meets Hwan, she is confident enough to be direct and honest with him.  This outspokenness is the thing that helps her win his trust and eventually his love.  Jeon So Nee does well in this role, but I wish they had continued to show her strong, independent side.  Her ability to fight and defend herself and her interest in examining dead bodies gives her a quirky, unique personality that gets left by the wayside as this drama progresses.  I would like to have seen her helping Myung Jin do more investigations.  

Lee Tae Sun as Kim Myung Jin 

Kim Myung Jin is the youngest son of the Chief State Minister.  But much to his mother's disappointment, Myung Jin isn't interested in political position or power.  He spends his time running his own business as a private investigator and herbologist.  The locals know him as a jack of all trades who solves problems like pest infestations and minor health issues.  Ga Ram comes to him as an assistant, but when he finds out her true identity, his feelings for her become something more than friendly colleagues.  

 ♥ Quick Reveal

I kind of liked the fact that Hwan finds out who Jae Yi is immediately.  There is no unnecessary build up to the idea that she is a woman disguised as a eunuch.  He knows she is his mentor's daughter and his best friend's intended bride.  While everyone else is kept in the dark as to her true identity, it was nice that Hwan knew from the beginning.  I think this also helped establish their trust in each other, as they had to protect her secret.  

♥ Twin

While I picked up on the idea that there must be 2 Tae Gang's right away, and I was sad that they killed off his brother as soon as they were reunited, I loved the idea that many of the scenes we saw with the Warrior Guardian were actually Tae Gang's brother.  Before his death, he tells Tae Gang that he was happy when he lived as him.  It brought me some joy to know that he didn't have to spend his whole life as an unhappy rebel.  Also, I think the fact that he couldn't help but like Hwan and in the end give his life to defend him, had a lot to do with the affection he was able to see and feel during his time posing as his brother.  

Prince Myung An

By the end of this drama, I really felt bad for Prince Myung An.  First he finds out he was a pawn used by his own 'grandfather" to kill his brother, who he loved.  Then he loses his other siblings when it is revealed that he isn't the King's son at all.  And once his mother goes crazy, he is left all alone and sent to live outside the comfort and luxury of the palace as a commoner.  And to top it all off, the poor kid has grey hair.  It seems like it might have been better for Hwan to keep him close at hand, in case someone tries to dispute his parentage and use him to create political strife.  It just would have been nice for the kid to catch a break somewhere along the way.

Han So Eun

As the young lady who almost became the Crown Princess, I wish we had gotten to know a little more about Han So Eun.  Obviously she was never going to become the true Crown Princess, with Jae Yi waiting in the wings.  But it would have been nice if we knew a little about her, so we could at least feel bad when she is murdered.  That whole engagement process and death felt like a waste of plot line that didn't have enough story to make us care.  

"Our Blooming Youth" delivers a nice happy ending complete with the death and destruction of our evil villains.  The Right State Councillor and his cousin are both sentenced to death for their roles in the Byeokcheon Rebellion and their many other crimes.  And the rest of their supporters are sent quietly into exile.  The Queen is finally overcome with guilt and eats the magic fish eggs that make her crazy.  The people of Byeokcheon are finally able to return home and start rebuilding their town.  And Sung On is appointed as their Governor.  Jae Yi and Ga Ram move into the house that Hwan set up for them.  After the truth comes out about the Queen, the King decides to nurse his broken heart by stepping down from the throne and putting Hwan in his place.  One year later, Myung Jin and Ga Ram have publicly declared their feelings for each other, so their marriage seems to be imminent, even if Myung Jin's parents have to pretend not to approve and disown him so they can be together.  Jae Yi is teaching as she has always dreamed, but she is waiting for Hwan to come to her so they can be together.  After the royal physicians and servants all declare that Hwan is hopelessly lovesick, he finally shows up at Jae Yi's door to confess his feelings and propose to her.  And with that, we finally get our happily ever after kiss.  And all is well in the Kingdom!