Jung Hae In has become one of my favorites, and this show was redemption for his last drama - Something in the Rain which ended so disappointingly. He was perfect in this, as was Han Ji Min, who has risen up to my favorites as well this past year.

My biggest complaint with the storyline is that the issues with the ex-boyfriend drag on way longer than they had any need to. I thought his role in the story would be done by episode 7/8, and they could move on to other issues. But that wasn't to be the case. As with SitR, One Spring Night has that realistic, raw feel to it, with great use of mood and tone.
My second and last complaint about the show is that, as also in SitR, the music was played too loudly in some scenes and although gorgeous music choices, they overplayed them quite a bit.

I loved the emotional Ji Ho and the forthright Jung In. I could relate to them. I loved Jung In's sisters as well, and wish their storylines had been explored a little more rather than the continuous merry-go-round with Gi Seok. Gi Seok's character was tied with Jung In's father as the least likable characters on the show. It made me both sad and a little angry thinking that Korean parents might actually be anything like Jung In's father. The other parents of the main couple were really enjoyable and sympathetic to me. And little Eun-Woo was adorable! I would also liked to have seen them interact with him a little more.

You'll see many of the same actors/actresses that Ahn Pan Seok likes to use, and they all are amazing.
But I'll warn anyone off of it that hated Something in the Rain. All the things that you may have disliked about it are still present in this drama, just with a better last few episodes. I'm well aware that my 8.5 rating is because I personally enjoyed the show and loved the actors, the music, and the romance, and for the sake of the romance with 2 of my favorite actors, was willing to overlook some flaws in the storyline.