[quick transmigration + sweet romance + not purely an animal story + one-on-one romance + both leads are pure]
After 25 years of soul-crushing life as an office worker, Ruofu finally dropped dead one day. Before dying, she swore that in her next life, she would never again work herself to the bone like a beast of burden.
But!!!
Nobody said she couldn't be human! Ruofu is reborn as all kinds of animals, but they all have one thing in common: they're beautiful and adorable, yet utterly useless with zero survival skills. To avoid starving to death, Ruofu decisively sets out to find a powerful ally and attach herself to his coattails. But as she clings to him, she starts to feel like he's looking at her in a rather strange way!
World One: [The fierce and domineering alpha wolf]
World Two: [The aloof and composed steed]
World Three: [The grassland's mighty lion]
World Four: [The god of the snowy forest]
[Content warnings: The animals may not all be real-world species; some may be extinct. The transmigration worlds vary, as do their eras, so don't overanalyze the details. Both leads are pure, there is male rivalry, it's a sweet romance, and the male lead is split into different incarnations. The heroine may become human in the final world.]