Act 20: Hina was Mamoru's Finacee... (陽菜さんは衛の婚約者だったの…　/ Hinasan wa Mamoru no Konyakusha Datta no... )

11:22 Park

According to that map, they're at Kawaguchi Green Center in Saitama.

12:30 Daichi, you're it!

The word used here, in games of tag in Japan, for "it" is "oni", 
a kind of demon in Japan.

13:19 Miniature Railway

In Japanese, this is called a "mini SL" where "SL" stands for 
"steam locomotive".

13:21 Scenic Slide

A kind of slide where kids can look out at the top before sliding
down.

16:11 Ami knitting

It should be noted here, that Ami knitting is significant. Since the verb
"to knit" is "amu" from which the root "ami" can be derived and that
the Japanese can also use the word "ami" (from the French ami/amie)
to mean "friend". There is symbolic word play here. With Ami knitting
together (ami) her friends (ami). The interpretation of this information
is up to the viewer.