Part-Time Friends / Bio Square - S2-E19
Continuity mistake: Part-Time Friends: When Arnold and Gerald get part-time jobs at the flower shop, while Mrs. Vitello explains things to them, she asks if she's going too fast, and in the next close-up, Arnold's apron vanishes, then it reappears.
What Does Blue Want to Make? - S1-E15
Visible crew/equipment: A boom mic is visible when Steve starts singing "We Just Got A Letter."
Midori no chikyû wa makasetoke - S1-E2
Other mistake: When Yurika restarts the Nadesico, one of the screens pop up with a huge congratulatory "SAFATY ROCK OFF." (00:18:05)