Not exactly co-founder, but for ReachExt K.K.'s new business line https://www.employmentjapan.com/we are looking for countrywise business partners. In a way the person or entity would be as good as a co-founder for his/her own country because the profit sharing will be as close to being a founder - though limited to the operations/business of one country.

In case of interest, please do check the details at https://www.employmentjapan.com/become-our-business-partners....