Kamen rider gavv

It seems you might be referring to "Kamen Rider Gaim" or perhaps "Kamen Rider Grease." However, there isn't a series specifically called "Kamen Rider Gavv" in the Kamen Rider franchise as of my last update in October 2023. Kamen Rider is a long-running franchise in Japan featuring various "Riders" who fight against evil forces, usually using unique belts and often with themes related to insects, animals, or other motifs. Each series typically features a new main character, storyline, and set of transformation items. If you meant a different series or character or if it's a new release that has occurred after my last update, please provide more details or clarify, and I'll do my best to help!