Among the many things I like about Kotoura-san, I have to give it full credit for this one - it continues to surprise me.
trying to dig up an onsen so that they might have a mixed bath with Kotoura (the rich make money without even trying to - such is life). The highlight of this chapter is no doubt Mori's cooking - which is apparently not only vile but highly hallucinogenic as well. This leads to a rather hilarious sequence in which she more or less tries to rape Manabe and he tries to get to second-base with a Kotoura-sized vase (much of this imagined, of course) before the three of them wake up together, only Kotoura wearing clothes. Mori's interpretation of Kotoura's innocent "You two were really going at it" remark leads to the best single comic moment of the episode, Oedipus Rex style.
flashback that does a very nice job illuminating her past with Muroto-kun a little (there's fair potential in that relationship I think - it's refreshingly different from the usual osananajimi dynamic). Manabe's real reason, meanwhile, in blocking Haruka out is that he's been working (wearing a bear suit) to earn enough to plan a surprise party for Haruka-chan's birthday. And of course he couldn't tell anyone, because then their thoughts would be subject to piracy by her - and as he admits himself, he likes to show off once in a while.