Hello Mr. Nakayama, the affiliate networks has to be developed by approaching several affiliate networks, as well as by running google and facebook ads campaigns to recruit quality affiliates.
The most relevant quality of affiliate for you will be those bloggers and writers who covers equities, stocks, mutufual funds, and financials, and other investing instruments.
I used to be such an affiliate myself in start of my 16 yrs long marketing career, so i have first hand experience of both side of thr table, and can build decent results for you.
we do on monthly retainer basis (tixed fee fpr monthly service) and we can renew the contract when both parties deem appropriate.
i would love to discuss it further with you. will wait.
Best, Gaurav