Here’s an idea of mine (and sorry for being away for so long): A mod for the PC version of Story of Seasons: A Wonderful Life that features the following altered characters:
Chubby Cecelia
Plump Molly
Blubbery Nami
Lardy Lumina
Hefty Gustafa
Rotund Rock
Porky Matthew
Tubby Gordy
Everything else (bar select dialogue relating to the modded spouses) would remain unchanged. The only side effect would be that depending on which character you choose, one of the female NPCs would become fat as a result, being as follows:
Vesta (Cecelia or Matthew)
Chris (Molly or Rock)
Lou (Nami or Gordy)
Flora (Lumina or Gustafa)
The side effect would happen beginning with Chapter 2: Branching (known as Chapter 2: Happy Birthday in the Harvest Moon equivalents) after choosing the plumped-up spouse of your choice.
This is just an idea I threw out there. If someone wants to make a mod like the one I came up with the idea of, be my guest.