Shibuya -- You might try Hobgoblin Shibuya, on Dogenzaka slope, at 1-3-11 Dogenzaka (tel. 03/6415-4243), open Monday to Friday from 5pm and weekends from noon.
Roppongi -- Directions are from Roppongi Crossing, Roppongi's main intersection of Roppongi Dori and Gaien-Higashi Dori.
Try Hobgoblin Roppongi, on Gaien-Higashi Dori in the direction of Tokyo Tower at 3-16-33 Roppongi (tel. 03/3568-1280), open daily from Monday to Friday from 5pm and weekends from noon.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.