For a first-time visitor in 2026, 5 to 7 days is the ideal duration for Tokyo. This timeframe allows you to explore the "Big Three" districts—Shibuya (Scramble Crossing), Shinjuku (Nightlife/Gyoen), and Akihabara (Tech/Anime)—without rushing. It also provides time for "Old Tokyo" in Asakusa (Senso-ji Temple) and a day dedicated to the futuristic art installations at teamLab Borderless in its new Azabudai Hills location. If you have 7 days, you can include a popular day trip to Mount Fuji (Kawaguchiko) or the seaside town of Kamakura. While you can "see" the highlights in 3 days, Tokyo is so vast and culturally dense that you’ll spend much of that time on the Metro; a full week allows you to actually soak in the neighborhood vibes, try different regional ramen styles, and experience the city’s world-class dining scene at a manageable pace.