If I sent someone a note via Streetpass, can he/she answer me via Spotpass or other ways?
Absolutely, i believe that there is an option to send notes via spotpass as long as they have internet. They can also streetpass notes to you.
Although it is possible to Streetpass Swapnotes to others, people may not be able to send you a reply via Spotpass if you two have not exchanged friend codes.
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