Honestly, this the the episode where Miku's growth shines the most. In the subsequent episodes Nino refers to her as "still not being able to express herself well", but it is probably the opposite: she is the one that is able to convey to Yotsuba the feelings of all the other 4 sisters, and any Miku's phrases here are so sincere and heart-felt that Yotsuba gets the courage to talk to Nino again. In this episode Miku says one of the best words I have ever read in manga, no exaggeration, and once again just makes me wonder: why Yotsuba?.. Miku is just so much more well portrayed, real & super cute.