Whew such an outburst from Koharu! Poor Izumi, she was just being a nice friend and all that but still I really like Koharu this chapter. Might repost my thoughts about this here:
Okay I don't glorify in any way what my dear Koharu did to Izumi, but the way the events were played were just perfect in setting up that outburst she had.
1. The suggestion Eiji had on her definitely affected her coz he's basically telling her to change the status quo, which she feels comfortable in. Now I say comfortable in a way that brings her a sense of agency, like going back to an old habit and in this case dating her ex.
2. That resolve of hers gets weaker when she finally sees Bessho and gets to talk with him, making her realize it's not helping at all coz she just falls even more for him, for his kindness and when she reflects on it she thinks how lucky Izumi must be to have such a man by her side, though this train of thought gets cut off when she sees Izumi herself
And then the inevitable happened. Koharu's actually self aware coz she noted that Izumi's the last person she wanted to see, but it isn't helping, coz her emotions are all ahead of her. I really like the escalation of things here coz they all just happened because of the circumstances Koharu was in and the consequences of such. And her finally breaking down and realizing where she did wrong was so satisfying I couldn't help but clap.