The Hyper-Kamiokande detector is planned to consist of an order of magnitude larger tank than predecessor experiment Super-Kamiokande's and ultra high sensitivity photosensors. The Hyper-Kamiokande detector is both a “microscope,” used to observe elementary particles, and also a “telescope” for observing the Sun and supernovas, using neutrinos.
For a full description, please visit the Hyper-K Overiew page here.