Over the years the follow Sanshinkai Letters have been published.
| Bibliography | ongoing |
| Sanshinkai Letter 1 | 2004-02 |
| Sanshinkai Letter 2 | 2004-11 |
| Sanshinkai Letter 3 | 2005-05 |
| Sanshinkai Letter 4 | 2005-12 |
| Sanshinkai Letter 5 | 2006-12 |
| Sanshinkai Letter 6 | 2008-02 |
| Sanshinkai Letter 7 | 2013-05 |