Look behind in this pic. you can find that escalator.
https://www.google.co.jp/maps/place/TOHO+Cinemas+Shinjuku/@35.6949748,139.7019714,3a,75y,1.5h,90t/data=!3m8!1e1!3m6!1sAF1QipOQ_V6-3-W8CcRDC4xGvYVIWE-aQ6MWfjLRGOlc!2e10!3e11!6shttps:%2F%2Flh5.googleusercontent.com%2Fp%2FAF1QipOQ_V6-3-W8CcRDC4xGvYVIWE-aQ6MWfjLRGOlc%3Dw234-h106-k-no-pi-2.9999962-ya1.5000076-ro0-fo100!7i10240!8i5120!4m12!1m6!3m5!1s0x60188cd82b4cf2ff:0x4e180e7a40fbffe8!2sTOHO+Cinemas+Shinjuku!8m2!3d35.6954153!4d139.7020545!3m4!1s0x60188cd82b4cf2ff:0x4e180e7a40fbffe8!8m2!3d35.6954153!4d139.7020545?hl=en