HAPPY SUGAR LIFE (Happi Shuga Raifu), by Tomiyaki Kagisora. First published in 2015 and first published in North America in 2019.
PLOT:
Satou used to have a reputation for sleeping around, but lately she seems to be settling down. Her new partner is sweet, innocent...and also a little girl. Satou would endure anything to stay with little Shio. She would work multiple part-time jobs. She would endure all sorts of bullying. She might even go so far as a little murder to maintain what she belives is their happy sugar life.