From east exit of Shinjuku station / Seibu Shinjuku station, walk to Yasukuni-Dori street,go along with Central Road which is between 'Don Quixote' and 'Tsubo Hach' until Toho Cinema IMAX,
then you'll see the big ‘I ♥ Kabuki-cho’ sign on the building on your right. There's 'family mart' convenience store on its 1st floor.