It's literally just Souta, Kyoko Hori's little brother that calls Izumi Miyamoto his older brother (and probably is actually his older brother, now, as a brother-in-law), and Yuuna, Souta's closest female friend from Kindergarten/Elementary. Clearly they're still going to school together 10 years later, and are having romantic feelings for each other. Pretty sure Yuuna was already thinking about Souta romantically well before now, but I guess she was waiting for Souta to say something first.I don't remember either of these characters lmao
You do realize they've been basically engaged since Christmas of last year of high school, right? Volume 9, chapter 63.what they still haven't married yet. I bet they will get engaged by the end of this time skip