User blog:A-chana/Interviews with Mothy

For those who are fluent in Japanese, here's a site where Mothy answers some questions. Here are some story-related questions I've seen; I'm not sure what exactly is being said since I used Google Translate, but they do seem to contain information.

Possible confirmation of the name of Gallerian's late daughter

The promise that Caspar forgot

Possible confirmation of Yufina x Kachees

As far as confirmation that it's Mothy goes, there's this comment on his Twitter that links to the interview page.