I see this isn't above a bit of jealousy scares, although given the bait early on it's probably par for the course.
We get a new named character after 20+ chapters of everything just being Izumi and Honami. And it's a new girl who possesses a mix of both tomboy and kuro gyaru traits. She's too powerful for this manga! Shiyu is like a storm in what was calm waters in this story. This chapter was probably a wild ride in Izumi's mind, nevermind the eyebrow-raising reveal that Honami ran away from home once. Honami denied it. Nevertheless, it's an intriguing plot point but it could be too heavy for this light and fluffy story.