What's the significance of ring worn on middle finger in this case?
Also, thank you for picking this up. It's delightful to see this story come to completion.
You’re welcome, and good question! I noticed the first time but forgot to look into it—from what I can tell, it seems the middle finger on the left hand (Ibuki) improves cooperation and one’s ability to read the room, and hence improves relationships. The right hand (Yūma) is for strengthening one’s will and taking action, and thus recommended for indecisive people.
That being said, I
have seen advice cautioning same-sex couples on the potentially unwanted questioning that comes from wearing a ring on the ring finger, so it could just be reflecting the unfortunate reality that Japan is still relatively conservative when it comes to LGBT+ issues. (The author seems to have done at least some research—i.e. two of the books Maika’s reading in chapter 9 are real books about diverse families—so perhaps this is the most plausible explanation.)
But if anyone knows any better I’m all ears!