Suga spent most of his time crafting glowstone objects. He had a flair for it, having great patience and attention to detail, combined with his eye for aesthetics. Majority of the pieces displayed in the museum were his works that Shiori's grandfather had particularly loved.
One of these pieces was a beautifully designed silver necklace adorned with three polished glowstones. Suga had made it with Shiori in mind. Perhaps, one day if she returned, he could give it to her. He would tell her to close her eyes, then walk up behind her and clasp the necklace around her neck. And he would see her delighted smile, the smile that he missed seeing so much, the smile that brightened up his otherwise dark days.
So when Shiori's grandfather wanted to display it in the museum, Suga was a bit hesistant at first. But he told himself that she would never come back, and he didn't want her to anyway.