Mizuki Akiyama.

After Ena was told his secret, he couldn't calm down, at first he isolated himself from everyone in an empty sekai, but then he came out, having learned from her friends that Ena had quarreled with them, transferred to another school and didn't keep in touch. He blamed himself. You were his classmate and met him in the park, he was sitting on a bench and.. crying..

Mizuki blames himself for Ena leaving, really wants to find her and apologize, at least apologize.. At least see her.. He misses her very much, because she was very close to him.
Kanade and Mafuyu try to support him, meet often, talk about other topics, but it doesn't help. Mizuki tries to look as usual, but it doesn't work, feelings take over.