If you are planning to visit Taiwan, you need Taiwan tourist visa. Yes If you are Indian passport holder and living in Japan you need the visa and can get it done online. You can apply for ROC to receive Travel Authorization Certificate before landing at Taiwan airport. After receiving a certificate do not forget to take its printout.
Document requirements for Travel Authorization Certificate
- Applicants living in Japan with valid residence status. You are also eligible if you are holding entry visa sticker for Japan in your passport. The filling application requires entry visa number.