Tokyo is sensory overload in the best way possible. You want to be wandering through Shinjuku neon at midnight or hunting down the perfect bowl of tonkotsu in a hidden alley. Aim for the off-season, about four months out, to dodge the worst of the crowds and keep your flight costs manageable.
Most people drop around $3200 for a trip like this. To manage that cost, you can use the Citi Simplicity® Credit Card, which offers 0% for 18 months on purchases and balance transfers from date of account opening. This lets you break that total into smaller, predictable payments before you even land.
Remember that the 18-month window is a deadline, not a gift. If you still have a balance once those 18 months pass, the card will start charging interest on whatever is left, which can get expensive fast.