The previous episode of Kuragehime pretty much finished off setting up the various aspects of its main characters and story, leaving this fourth instalment as pretty much the first time the show can let loose and really start working on those core tenets.
This begins via what should be a fun occasion of roasting potatoes on a bonfire, but it's an event which brings back some tough memories for Tsukimi regarding her sick mother... not that she's given too much time to dwell on this as the Sisterhood are interrupted by a panicking Kuranosuke who has finally learned of the plan to demolish his new friends building in the future. If he was expecting this to set off an all-out panic amongst said building's residence then he's in for a disappointment, as the only response he gets is one of general apathy and the assertion that those who can be bothered to protest against the development will sort things out.
From here, the rest of the episode is all about Tsukimi, or more precisely her part in what is fast becoming a love triangle between herself and the two Koibuchi brothers, as a simple trip to visit the jellyfish at an aquarium to sooth Tsukimi's frayed emotions turns into a rather more complex affair thanks to a blend of Tsukimi not wearing her glasses (allowing her to be herself in front of Shuu for the first time), her emotions getting the better of her as memories of her mother resurface, and Kuranosuke finding himself feeling an unexplainable jealousy when he witnesses Shuu comforting Tsukimi as a result. Come the end of the instalment, it seems like everyone's emotional stability is thoroughly messed up in a number of ways - which is exactly what we like to see in the name of comedy and drama.
As per my comments last episode, it's actually really quite hard to explain how a series that has such a deceptively simple story manages to be rather deep in so many ways - away from its slapstick comedy (Banba's hair gets all the good jokes this week, it's going to need its own spin-off series at this rate) there's a lot of emotional and psychological depth to be explored here, whether it's Tsukimi and how a mixture of not wearing glasses and visiting an aquarium puts her into her element (which felt surprisingly familiar; put me into a scenario where I can talk about stuff I'm interested in and I'll yak anybody's ear off whereas you'd be hard-pressed to have such a conversation otherwise) or Kuranosuke's predictable but still nicely realised jealousy and emotions throughout the episode. It might not seem like it at first glance, but there's so much going on here with these characters you could probably write a book on each of them, and processing all of this subtle information beneath a fun romantic comedy is incredibly entertaining and fascinating in equal measure.