In episode 7, Asahi is so embarassed at his tennis skills that he tells Yume not to come to his tennis match and cheer for Haruhito instead. Yume leaves, worried for him.
Yuni's backstory. He never got a partner and didn't come to life until The Nightmare Queen found him, then he made two small plushies out of loneliness.
In episode 28, we learn that Maira's mother died on her birthday, and as if that wasn't sad enough, check out her dream that episode. The first part is more like a flashback, filled with memories related to her times with her mom before her demise, and after Yume leaves, it switches to a more Dream Sequence-like part where Maira's mom bakes a cake and is introduced to Peko.
Haruhito's flashback dream in episode 37, which features instances of Akihito acting better than him on everything.
In episode 37, Yume gets nightmares about having to say goodbye to Mew, and in episode 38, it gets to the point that she just can't bring herself to use the Mewkle Stick in fears of parting with her.
