For a balanced 2026 Japan itinerary, the most common recommendation is a 5:3 ratio—five days in Tokyo and three days in Kyoto. Tokyo is a gargantuan megalopolis that requires more time because of its sheer diversity; you need at least one day for the "traditional" east (Asakusa/Ueno), one for the "modern" west (Shibuya/Shinjuku), and extra days for specialty interests like Akihabara or day trips to Nikko and Hakone. Kyoto, while dense with over 1,600 temples, is more geographically contained. Three days allow you to cover the "Big Three" regions: the Eastern temples (Kiyomizu-dera/Gion), the Northern pavilions (Kinkaku-ji), and the Western bamboo groves (Arashiyama). If you are a fan of "slow travel" and traditional arts, you might flip this to four days in each. However, since Kyoto also serves as the perfect base for a half-day trip to Nara to see the deer and Great Buddha, adding a fourth day to your Kyoto stay is highly recommended to avoid feeling rushed during your cultural immersion in the ancient capital.