There is luggage storage in the airport with details available here.
They have multiple day options:
When I asked for a few day discount, they said no, but give it a try.
Source: TripAdvisor Discussion
Your initial problem will not be where to store your bag, but getting access to it in TPE.
By default, your bags will be checked through to your final destination - in your case that's CTS/Chitose Airport. In order to instead have your bags delivered to the baggage carousel in TPE you will need to ask the staff at the check-in counter in SFO to "short-...