It's beyond me how people can defend Hima, i get she wants her friends to get along but that's just intrusive, even shiho is mad. I can't stand people that believe they're above all conflict and can solve everyones problems , like dude just let them figure out their problems by themselves . It's fine to give advice but it's annoying when You start meddling in people's problems
Some people don't learn that lesson until they're older. Some times they don't learn at all. Keep in mind these are high school girls dealing with overwhelming sensations and a series of firsts. They are inexperienced. It's a period of time that's usually a hot mess of rampant emotions and illogical/impulsive decision making.
Its true tho
I wouldn't go so far as to say Hino thinks she's immune to conflict, or some know-it-all who has the right answer. It's more like she's oblivious to context and is desperate to keep relationships afloat. She hates seeing people fight, and it's interfering with her better judgment.
I'm not saying she's making the right call here - it would have been much better to stay out of it. But she has the guts to take on an immovable girl with a condescending attitude like Shiho and still openly declare her support for both parties. Not many people who stick to someone like Shiho after that performance.