Episode 6:
That short moment that Isaki had may turn out to be a sign of depression or something with depression as as a symptom. One of the reasons depression is missed sometimes is the person playing a role of "always bubbly personality", but sometimes it may show cracks like this. It would make a lot of sense, since insomnia can cause depressive episodes, and she is also falling in love, which cam cause those, as well, while self-evaluation of her importance for the club may also be not great, when compared to Nakami (at least from Isaki's perspective).
