Miyako's fears of interacting with others in public calls to mind the many instances of people suffering severe shyness in real life.
Other
Episode 3:
When Miyako is making costumes for the girls, she doesn't have one ready for Hinata. And when Miyako gushes over Hana too much, Hinata gets mad and calls Miyako a stupid jerk causing her to sulk and for Miyako to feel bad. Miyako tries to console Hinata as they take a bath together as Hinata says she was upset because she felt left out.
Episode 5:
Miyako breaking down whilst admitting to Kanon and Koyori that she wasn't the person that they thought she was according to the rumors. However, it becomes touching when Kanon states that she was even better than what the rumors entailed.
Episode 12:
The school play is about an angel who falls in love with a human girl but because of their lifespans, the girl declines her affections. The angel then embarks on a journey to become human to be with the girl...only to realize that she died by the time she made her way through the mountains. However, it later leads to Tears of Joy as the angel falls in love with the human girl's granddaughter, and when they died, the angel reunited with her first love.
OVA
Episode 4: I'm Your Big Sister combines this with Heartwarming Moments. It's a flashback of when Hinata was born. Baby Hinata constantly cries as Chizuru tries to comfort her. When she introduces her to Miyako, she cries even harder making Miyako feel insecure. Then she finally stops when Miyako holds her. In general, seeing Baby Hinata cry can break one's heart. And seeing how much more cheerful Miyako was a child can be sad knowing something might have happened that caused her to be even more isolated from the outside world. It can also hit hard with people suffering from nostalgic depression.
