KAGRA Future Planning Committee (FPC) has been approved by KAGRA Science Congress (KSC) in Dec./2018. FPC is discussing about the KAGRA+ upgrade plans after achieving the current design sensitivity at O4. Pre-discussions on the KAGRA+ have already started two years ago and a few possible candidates (Low Frequency, Heavy Mass, High Frequency, etc.) have been suggested. Based on these idea FPC are making more realistic plans and writing a white paper. In this KAGRA-Virgo-3G workshop, we would like to discuss which technologies are common with 3G and look for possible collaborations.