Is freelance English conversation tutoring viable for a 2-month stay in Tokyo?

I’m a US finance student planning to spend about 2 months in Tokyo this summer. I’m trying to figure out if doing freelance English conversation tutoring would realistically be viable during that time. An older Japanese woman recommended that I consider doing it while I'm there. I already have money for rent and plane tickets, so I don't need to make that much, as long as I can buy food and pay for transit. Her idea was to do English lessons with people who want to learn more conversational or business oriented english. I'm 20, but well spoken. I know a lot of English literature and am easy to talk to. I don't know Japanese but I'm looking to learn some in the next few months.

Is there a need for this, or is the market already over saturated with people just like me?What would be the best way to find clients?
Would I be better off connecting with a school or going through a third party?