Since its inception in 2023, the concept of "C-H bonds as the dormant species" to control chain growth has emerged as a promising, though still evolving, strategy for precision polymer synthesis. Beyond offering a simpler polymerization method, this concept is expected to promote unprecedented reaction pathways. In this study, we report the first vinylogous anionic ring-opening polymerization (ROP) of vinylidenecyclopropanes. Cooperative La(OTf)