How long will $6000 USD last me?

I’ll be arriving in Japan at the end of August this year, and want to stay for 2-3 months. I was planning a month in Tokyo, split a month between Kyoto and Osaka, and I haven’t decided where to spend the rest of the time. I will be eating street food and from convenience stores, staying in hostels/airbnbs, taking the cheapest transportation options, and will not be buying many souvenirs since I will only have a backpack. I will also not be doing super expensive activities, and I’m not a big drinker so I wont be drinking a lot. Based off of everything I’ve read online, I’m thinking 6k could last me three months. I’ve already booked the flight. Is this reasonable?