1x3 - Celestial Method

While on an orienteering trip with the others, Nonoka feels confused as to why Shione is so hostile towards her. The girls soon encounter Noel along the way and have her join their group. Later, when it seems that Shione has strayed from the group, Nonoka goes off in search for her, unaware that Shione had actually gotten ahead of them, winding up lost herself. After ending up at an abandoned kindergarten and eventually being found by Noel, Nonoka remembers that not only was she friends with everyone seven years ago, but she was the one who suggested they call forth the saucer, with Noel revealing she is the saucer itself.