I very much hope Hikari is only a threat in Yuu's heart.
Her mind hasn't seemed to fully catch up on why she feels so unsettled; she's aware that it's a good thing that Haru can talk to someone else so openly, but......well, I get it all the same, Yuu.
Haru's not thinking about that sort of thing as of yet, it would seem, but. I know my own preferences, and while romance isn't the focus of this series, I connected with Yuu from the get-go so I just want her happy.
But it's also super nice to see that Hikari had someone in her family that actively and enthusiastically supports her dream. That's just...a huge deal for any creative, much less someone wrestling with adolescence at the same time. Haru (and ostensibly Yuu) being in her corner is one thing, but you gotta have adults, and hopefully ones you're already close to, in your camp as well--if only for the emotional and mental buffer that will provide in pursuing something that's admittedly very difficult to achieve.
But Hikari proves incredibly resourceful, if a bit ....sketchy on the financial side. Getting them not only a place to practice that works for Haru, but even a incidental lead on making some money for themselves and their dream on top of that? Very much the windfall. And, potentially more practice for Haru on the social side of things (being a public-facing job and all), as well as more potential idea mining for Yuu's "youth-focused" songwriting.
Thanks for continuing with this series. Can't wait for the next.