Nice one as usual.
Maybe it’s not yet clear at this moment, this episode is a super important setup and basis for the later episodes, the little details do matter, you will figure out when those happen, and it’s really worth a rewatch after those episodes. (Ep4and Ep8 are heavily linked together)
And btw, those locations and aquariums are real locations in Tokyo, the anime draw those views exactly as the reality, and I did a trip for these locations, and it REALLY took a day! All around Tokyo! That’s why the anime shows the changes of the location and the color change of the sky, to indicate they took a long time. And it also shows Karen did take a lot of effort chasing Hikari, and also with a lot of love.