Even though I become a side character, I'm being adored by an overprotective duke

I was reincarnated as a Side Character from an Otome Game and my fiancé is a handsome Duke. I've been transmigrated as "Leticia", a side character from an Otome Game. I was then forced to take Lionel as my fiancé by my twin sister (who by the way, has the worst personality). The first time Leticia met Lionel, he was nothing but chubby and fat, just as the rumours said he'd be… However, me being me, I realised that Lionel is an unpolished gem with potential to shine, so I decided to re-invent him. Even if I'm a Side Character, my days of doting on my fiancé began when my fiancé transformed both inside and out.