We propose a new project: Hyper-Kamiokande to explore neutrino CP violation and proton decay with much better sensitivity. Hyper-Kamiokande is a successor of Super-Kamiokande. Hyper-Kamiokande has one Mega-ton mass with 100,000 20-inch photo-sensors. In the seminar, we introduce the basic design of Hyper-Kamiokande and its full physics potential. With Hyper-Kamiokande, we could discover neutrino CP violation in 3 sigma level in 76% region of CP violating phase delta. For the proton decay, we can search up to 10³⁵ years with e⁺π⁰ mode and 10³⁴ years with νK⁺ mode. We plan to start the construction of Hyper-K in 2018 and data taking in 2025.