We have successfully started a project of hypernuclear γ spectroscopy with a germanium detector array called Hyperball. Transitions in 7ΛLi and 9ΛBe were observed and information on the ΛN spin-spin and spin-orbit interactions were obtained. Hypernuclear shrinking effect was also observed from B(E2) in 7ΛLi. More experiments to determine all the ΛN spin-dependent interaction terms are in progress at BNL. Various types of experiments are planned with the upgraded Hyperball in the future. In particular, γ-weak coincidence method is proposed for B(M1) measurement.