Each episode is sweeter than the last. The flashback was beautiful and really showed us why Yukari decided to become an idol. The bond she shares with Nana-chan has such a beautiful backstory; seeing how they care for each other makes the whole thing completely worth watching. Yukari-chan shouldn't be so hard on herself. You can tell she hates failing and pushes herself to the absolute limit, which is why Nanako's help really brings a balance to her life.