I don't have much to say about this series, other than the fact that it was absolutely lovely in all its aspects.
The story is very simple, but it's also shown in about one hour in total (every episode is 5-10 minutes long and there's 10 episodes) and no time was wasted at any moment. The characters were defined very clearly and got very good characterization, all through the dialogues they have with each other through video-calls, with very few exceptions.
The actors all did an amazing job as well. I've heard that this series was filmed with phones, which makes it even more impressive. Everyone seemed natural and I got really invested in the main characters and the development of their romance. I was afraid that the two protagonists would not fit with each other as a couple, but in the end they seemed to have great chemistry and I loved to see their moments together. I also really liked the mix of Japanese and Chinese.
It's easy for very short series like this one to feel rushed or like something is missing somewhere, but there was no issue like that in here. It surely won't keep you on the edge with loads of angst and drama, but I believe that this is also its main charm: since there isn't any dramatic event in the entire series, it's very good for whoever has an hour to spare and wants to watch something cute and relaxing.
I strongly recommend watching it!