A nice story, and it does a good job at allowing you to get to know the characters with the limited amount of time. (it being a oneshot and all)
I really enjoyed the fact that this story is more realistic in the sense that Ten doesn't immediatly switch up on Yuzu. It wouldnt be realistic to agree to date someone you've only known for a couple days and know very little of. (I don't think Karin ever talks about herself, and Ten never asks to know more about her, only asking about Yuzu) And i really like how Karin is super understanding of the fact. And i think that him staying true to Yuzu made Karin like him even more. Due to her having a monologue prior, talking about how she doesn't like the idea of giving up on someone, even if they like someone else. Making him align with her ideals more. But in the end i do think Karin and Ten are the better match, same goes for Yuzu and Haru. And i really hope that these two pairs are what the author had in mind if he ever continued the story.
I dont wish for this to be serialized, but i do hope that the author gives this one more chapter. Allowing us to see more of Yuzu and Haru, how that develops. And how the dynamic between Karin and Ten changes now that he knows that Karin likes him. It would be really interesting to see. As Karin's challenge "Let's see which one of us can get his or her loved one first" makes it sound like she won't be pushing Yuzu and Ten together, instead fighting for his attention.
All in all, great characters, (atleast the ones that are somewhat explored, which is like only Ten, every other character is very surface level rn as there isnt enough time to explore them, but they're still very likeable) and a nice story.