Ah, good to know. Thanks for the tip!
If it's a basic text replace crawler, could still work. I don't think there's any harm in giving it a shot, jsut keep a backup of the data/lang/en folder. If the game still launches after your patched, try the first day and see if it did replace the character relationships. If it crashes, just reset your data/lang/en folder.
It's crap when it's forced and the obvious truth is the author always meant characters were blood related. In Glassix, Kei is clearly living in his step family, his father was the owner of the glasses before him and had his own harem, too busy to take care of his son he found Aiko to take care of him for him. If you really want incest for MC and keep the story, it would be better to create a new mommy character for Kei and add her to the game. I never thought that much about Kei's mother so I don't have any back story for her.
Hm, you're right. After checking the code, there's no event to unlock their sexy work outfits. The sexy casual is bought in the shop but the sexy work can't be unlocked without editing files. I'll check with Carpe but I think it should require a new quest at the townhall like the other city employees. Thanks for the report.