The spring 2017 anime series Kado has some solid distribution on Crunchyroll with them having both the subtitled and dubbed options.
The series has set Kazuya Murata as the general director and Masaki Watanabe as the series based on the scripts by Mado Nozaki.
The opening features the song “Tabiuta” by M.A.O. while the closing sequence has “Eien no Kotae” by HARUCA.
A mysterious person (?) Yaha-Kui Zashunina who comes out of Kado tries to make contact with human race, and Shindo in the cube has to work as a mediator between human and Yaha-Kui Zashunina.