T2K consists of a near detector, ND280, and a far detector at a distance of 295 km. The far detector is Super Kamikande (SK), a 22.5 kton water Cerenkov detector. ND280 is a magnetized detector to study neutrino neutral and charged current interactions. To match DUNE and HyperK, T2K is upgrading to T2K-II. The neutrino beam power increases to 1.3 MW and the upgraded ND280 will start taking data in 2022. The angular acceptance of the detector, mainly forward, is improved to match SK and will double the statistics using SuperFGD, a 3D array of 2M 1cm cubes using independent wavelength shifting fibres to reconstruct the event in 3D, with range and dE/dx information and cm precision. Prototypes were built and exposed to appropriate beams. The SuperFGD concept will be presented as also results of the performance studies of the prototypes, and some of the technical challenges of the final SuperFGD will be discussed.