Anison reports that the lyricist is 椰子木小夏, read Konatsu Yashiki. Every other website goes with 柚子木小夏 (first character is different), which might be Konatsu Yuzuki, but it's just a one-off lyricist so I'm not sweating it.
The BGM composers are on the back scan, but it's next to impossible to make their names out. Hiroyuki Nagashima lists the game on
his works list, so that confirms him, and Hisayuki Horiuchi has worked with him a few times, like
this thing and
this other thing, so I'm feeling pretty good that the second dude is him.