Absolutely loved the premise but the execution by the writers was problematic in a couple of ways. The actors are good and the series is interesting despite the shortcomings. Overall worth a watch, especially since it's so short. Possible triggers for child molestation (though details are not shown or talked about) and... I don’t know what to call it, read the next paragraph for more.

As the series summary states, one of the main characters has a split personality disorder. Noah is the adult protector identity and Yu Shi is a stuck in childhood identity.
The biggest issue for me that made me uncomfortable from the start was the sex scene with the Yu Shi identity, who is mentally like a child even though the character is physically around 30 years old. And it's implied that Yu Shi was molested by a man when he was 5 years old, which makes sex with that identity even more cringe. (And later in Ep 1, the costuming decision to dress him in a shirt with Sesame Street characters was disturbing). Thankfully, all further intimate scenes were between Noah and Wu Zheng.

This morally questionable dynamic with Yu Shi stayed uncomfortable in my mind and negatively affected my overall rating. I like that Wu Zheng accepts both sides of YuShi/Noah, but he seems to have romantically fallen for Yu Shi first. Falling in love and getting physical with Noah, who is an adult mentally, is completely different than doing so with Yu Shi, in my opinion.

STRENGTHS
I loved the interactions between Noah and Wu Zheng. They were both natural and believable actors. Their chemistry was strong and their intimate scenes were full of desire.

Once I was parteway into Ep 2, I was invested and wanted to see how Noah/YuShi and Wu Zheng's relationship would play out.

All of the music chosen fit the mood and enhanced scenes. It blended well and was never distracting. The cinematography was consistantly good and created a cohesive feel.

FYI watch past the end credits in Ep 4 for another short scene!

WEAKNESSES
It would have been much less confusing and easier to connect with the characters sooner had the story progressed in a linear fashion instead of jumping around. It felt like they started in the middle of the story just to grab viewers with a sex scene, then jumped backwards to fill in more of the emotional connection, then forwards again to finish where they left off.

The secondary relationship was completely and utterly unnecessary. I wish they had spent the measly 5min of their story on the main couple instead. The ending for the main couple in ep 4 felt rushed and all issues and lingering questions just swept under the rug for the fairytale ending.

The therapist seriously violated doctor-patient confidentiality in two different scenes, which irked me (a careless, inaccurate, and insulting portrayal of that profession).