Right next to kabukicho, shin-okubo station and shinjuku station! There is a downside to the proximity to those areas though. Since it's so close to nightlife hubs, we had to deal with some noise (loud drunken conversations and laughter mainly) from partygoers walking down the street right outside our second floor window late at night. Be aware of that if you're a light sleeper. If that sort of thing doesn't bother you, it's a great location.