7화: 쇼코는 루리와 함께 바다 유리와 실리카의 색 과학을 탐구하며 친구들을 찾는다.

7

Schoolgirl Shoko loves rocks, but receives no support until she encounters Ruri and company investigating sea glass. We learn different ways for silica glass to gain colors, including by thin-film interference. A day of searching for old bottles on the beach gains Shoko new friends with a shared interest. Ruri learns that her name is an old word for blue glass. (Source: Wikipedia)