Raman scattering can provide a wealth of molecular chemical information, but it is basically a highly inefficient inelastic light scattering process between photon and molecule with a very small cross-section. Raman scattering signals are often poorly reproducible, meaning that very strong and controllable amplification mechanism, such as SERS(Surface-Enhanced Raman Scattering) or NERS(Nanogap-Enhanced Raman Scattering), is needed to obtain measurable and reliable Raman signals. Plasmonically coupled metallic nanostructures with ultra-small (∼1 nm or smaller) nanogaps can generate very strong and controllable electromagnetic fields that can generate strong NERS signals from Raman dyes inside the nanogap. Therefore, plasmonic nanogap-enhanced Raman scattering (NERS) can be defined as Raman scattering signal enhancement from plasmonic nanogap with ∼1 nm gap size. In this talk, I will overview recent breakthroughs, advances, application, and prospects of plasmonic nanogap-enhanced Raman scattering with metal nanogap particles revealed by single-molecule/single-particle-level Nano Raman spectroscopy showing that these plasmonic nanogap particles can generate ultra-strong, quantifiable Raman signals in a highly reproducible manner. References [1] H. Lee, S.M. Jin, H.M. Kim, and Y.D. Suh, Phys. Chem. Chem. Phys. (invited review article), 15, 5276 (2013). [2] D. Lim, K.-S. Jeon, H.M. Kim, J.-M. Nam, and Y.D. Suh, Nature Materials, 9, 60 (2010). [3] J.-H. Lee, J.-M. Nam*, K.-S. Jeon, D.-K. Lim, H. Kim, S. Kwon, H. Lee, Y.D. Suh, ACS Nano, 11, 9574 (2012). [4] H. Lee, G.-H. Kim, J.-H. Lee, N.H. Kim, J.-M. Nam, and Y.D. Suh, Nano Letters, 15, 4628 (2015).