- Birth: ?
- Death: 1863
- Japanese: 佐伯 又三郎 (Saeki Matasaburou)
It is unknown exactly when Matasaburô joined the Mibu Rôshigumi. There is a record that he gave a Kenjutsu demonstration match for Lord Matsudaira Katamori. He killed Sasaki Aijirô and was later assassinated himself.
- Shinsengumi Taishi Den (新選組隊士伝) Gakken
- Shinsengumi Zentaishi Tettei Guide (新選組全隊士徹底ガイド) Maeda Masaki
- J-Wikipedia Hirayama Gorô