Kazoku ga Ai Oshikute Rikon Dekimasen

I found myself lost in a novel world, possessing an utterly ordinary supporting character. I intended to live quietly, but swept along by events, I ended up marrying the heroine's father. My plan was simple: “Make the daughter happy, then divorce.” That was all it should have been.

But the daughter was adorable, and her husband clumsy yet kind. Smiles gradually filled the once-cold house, and her “divorce plans” began to waver alongside her growing desire to live in this home. Despite misunderstandings from others, family complications, and the original story's “separation route” standing in their way, the three of them slowly reclaim the warmth of family through small daily choices.

(Source: Piccoma, translated)